To stipulate minimum number of nights at home for DD?

Yes I agree with @Rubiconartist

For tonight keep everything light and cheerful, no pressure or what can be perceived as pressure. Chat about random stuff like any Netflix recommendations or whatever let her see time with you can just be relaxed down time with absolutely nothing particularly in depth or serious to discuss

If someone told me to be at home more so I could spend more time doing house work, I would want to stay away for longer.

Can I suggest you don't try and have a heart to heart with her unless she comes to you.

I know you want to but it might push her further away. You're going through what millions of parents have and will again and you need to fight the urge to resolve anything and problem solve.

Be chill, enjoy her being there and her spending time with her sister. Show her that being home can just be nice with no pressure, no deep and meaningful chats etc.

Wow this thread has turned into an absolute pile on.

I hope you have a nice evening with your DD and a chance to reconnect.
Hopefully the total immersion of the past 8-12 weeks is wearing a bit thin and things will cool off and get back to normal a bit.

If she does get on with your partner/her step dad then either he or her father might be the best people to ask some gentle questions about whether this is a controlling relationship. Is she seeing other friends without the bf for example ? What is the 6th form doing to blow off some steam when term ends.

OP, this will pass. I’ve been where you are, and naturally you are upset and emotional. You’re bad cop to everyone else who are basking in the good cop role.
Firstly, the boyfriend. She’s besotted with him. It might be long term or not, but right now he’s in her life. Paint on a smile and welcome him in your home.
Secondly, you’re her mum and always will be. You’re her safety net, so you will always get the brunt of her frustrations and moods. Is it fair? Nope. Is it normal? Yes, absolutely.
I set boundaries, DD pushed them. She flounced off to her dads or the boyfriend more than once. I didn’t try to stop her, I waited for her call or text and always told her I loved her and the door was always open. A lot of what you’re going through is part of her growing up. She will make mistakes, let her. Let her know, unequivocally, that you have her back, always.
My DD and I are very close, and recently, with a different partner, bought a house close to me, because she wanted to be near her mum. If you can, take a step back and try not to see this as an affront on your character. Don’t make any changes until the dust has settled. I wish you well. If you take the pressure off yourself you’ll take the pressure off her too.

OP, you're a great Mum!

You raised her alone for 9 years, and have provided her with a safe home. This is why she feels safe enough to push her boundaries and test life out with a boyfriend like this.

Swearing is unacceptable, but not entirely unusual.

I hope your talk goes well. I would avoid comments to her like "I miss you" as to a teenager whose hormones are raging that may well come across as emotional blackmail. Maybe say instead just that you enjoy spending time with her.

Some PPs have been awful to you on here, and I am honestly shocked by it tbh. Your MH is clearly making you spin out and you obviously need some help, but remember how well you have raised her so far and just trust your instincts..

See about inviting the boyfriend for dinner at your home as well.

You need to make it clear to her: this is a family home, and everyone has to contribute. It’s not a hotel where she can expect everything to be done for her. She needs to start pulling her weight and taking responsibility for housework and chores.

Even in shared living arrangements, like renting a room, there are basic expectations for cleaning and helping out. It’s not fair for her to leave everything to others—being part of a family means sharing the workload.

I know what you're going through is incredibly painful. However, for you own sake, I wouldn't change anything for now. It could backfire. She won't understand your motivation and could think you've decided that she matters less if you give her room away.

What happens if the relationship ends? You need her to feel that she can return to you and that nothing has changed. If you do anything now she could resent you.

You don't have to be wrong for her to feel that anything you do is wrong. Hopefully she'll come to her senses.

It must be unbearable for you.

No, absolutely not. None of us are perfect are we. Which is why I suggested to OP it might be wise to pick her battles and separate any issues with the daughter behaving unacceptably or leaving the place in a mess when she is home (which is about basic consideration for others) from the emotional hurt OP is feeling about her being with the boyfriend more and home with the family less, as those are OP's feelings that she needs to deal with herself, and not make her daughter responsible for them.

When I was 18 and in college I used to spend every weekend at my boyfriends house, I think that's quite common. I did come home during the week though but obviously spent a lot less time at home. I moved out about a year after starting uni too but my parents never had a problem with me spending time away from home/spreading my wings etc.
Could you sit down with your DD and just tell her how you're feeling? Be honest but not too much and just say how it makes you feel? If I knew my mum needed a bit of TLC and was feeling a bit low I'd 100% have made the effort. She may just not realise how much it upsets you

I think it sort of goes two ways, yes you have every right to want to spend time with your daughter that than being used as an occasional hotel however the flip side is you need to be interested (or pretend at least) in her life and that includes her boyfriend. I've been through the first loves stage and the key for me was getting to know the boyfriend de jour. (i admit slightly complicated by having a little one in the house). Invite him over, get to know him, accept that she is smitten.

I know it probably won't last and I'm not suggesting that you invite boyfriend s around after 2 dates but once they are established I embraced the situation and it meant I had a happy house. My dd is still with her dp she met at 17, 6 years ago and have their own house

She’s meaner and ruder to you than other family members because you are her safety person. She knows you will always be there so like a teenager she treats mum the worst. I was mean to my mum when I tried to spread my wings - teenagers are basically grown up toddlers they act the worst for mum as they feel safest around mum- an annoying irony of being a mum.

It’s new young love don’t change her room as she needs to know she has her safe haven to return to if things go badly with the boyfriend. She will come back to you and want to spend time with you eventually - just don’t push her away while she’s spreading her wings

Maybe it's a communication issue - and try things like this:
https://www.amazon.co.uk/How-Talk-Teens-will-Listen/dp/1853408573

My Mum picked fights - some justified most could have been avoided -with older sibling around this age - then when he wouldn't commit to doing what she wanted - she did same as you did do you want to move out he heard move out - and did so into a squat - it was 90s fucked their relationship to this day TBH.

I'm surprised you are surprised she staying away TBH - when she round you seem to be nit picking round housework and having conversations suggesting idea she not welcome. Moving out this day and age not really viable - so she staying away and avoiding you - to avoid arguments and being kicked out - that what I learnt to do as well though I couldn't stay away rural location I stayed in my room as much as possible and clung on till uni getting more withdrawn and then told them as little as possible.

Absolutely, sorry I should have said not something to answer but maybe have a think about

Okay this could be improved.
You mention though that you lived with your step mum. I wonder if that experience is affecting how you are reacting to your daughter?

To those who genuinely care and would like an update: daughter is home, her friend is with her. I plan to have a heart to heart with her once friend has left as she isn't planning on going out tonight. She's currently playing with her sister and has asked me if she can do anything to help (!?), which was pleasantly surprising. I will update following my chat with her.

Well that sounds more positive OP, hope it goes well.

I noticed you mentioned your dad and your step-mum, and not your own mother.

Is it possible that if you didn’t have this stage with your own mother, you’re taking this very normal teenage behaviour as a rejection because you haven’t experienced it from her side? Like lots of people have said, teenage girls and their mothers are often horrible to each other and then get close again when they’re older, it’s a really normal dynamic (unfortunately!!)

To be fair OP, there have been a range of posts and some have been horrible granted and some have had sympathy and empathy for your position. Some others have tried to give advice which you come across as not wanting to heed. I see you’re still blaming the boyfriend because he’s the only difference which, looking at it black and white, is true but this isn’t black and white.

I have offered anecdotal advice because I’ve been that teen. I could see how it was breaking my mother but I also could see that I wasn’t responsible for her reactions and I was in loving relationship where I was doing nothing wrong. I understand to you it feels like your world is falling apart but it’s not and you have to, for your daughter and for you and all your mental healths deal with this better. It’s hard in the middle of it and it doesn’t make you a bad parent, especially whenever you believe it’s coming from a place of love, my mum did too but it nearly wrecked our relationship and it was only saved by the fact that my mum apologised and took full responsibility for it for putting her feelings and fears ahead of mine.

Or your DD could invite him if you reassured her that he would be welcome.

But from what you’ve said, she’s not in the house too often to be making a mess. Just going her dirty laundry back in her room each and every time.

You've done nothing wrong as a mum. I was like your DD at 17 when i met my first serious bf.
It won't last. But in the mean time just ask her to tidy up the shower after herself and tell her that as she is never there you'd like her to swap to another bedroom so you can make use of the space.

I'd still do her washing but only IF i was putting a wash on anyway but that's just me.

I wouldn't pay for her phone though, she is earning and 18 so that's her bill now.

Good luck OP😘