@teenmumstress24
I don't think it is reasonable to insist that your daughter is home for a set number of days/nights per week. (Though I understand why you would wish to do this and I sympathise with your feelings that you are losing your previous relationship with your daughter.)
However, you would not be being unreasonable in establishing basic grounds rules of mutual respect. This is only natural when you have multiple people sharing a space (which your daughter is technically doing, even though she's currently rarely there.)
In some respects, it seems like your daughter is behaving like a typical teenager in the throes of newfound love. She has only been with her boyfriend for a few months and it all feels fresh and exciting and she's very much in that besotted stage right now. That's pretty much par for the course for most people at the start of a relationship, regardless of how old they are - there's that initial period where you can barely stop thinking about them.
In other respects, however, your daughter seems to be being thoughtless at best and at worst, disrespectful to you. So I think there's nothing wrong with making it clear that there are expectations of a basic decent level of behaviour.
The issue is in how you communicate this to her without it seeming like you're lecturing her or having a bit of of a go at her. You wouldn't necessarily be wrong to have a go at her about it, but practically, doing so would probably only make her angry and bull-headed. So you'd need to think about how you can raise these points with her in a way which is unlikely to make her feel defensive.
I'm very sorry about the emotional distress this is causing you, and you are doing the right thing by trying to seek some treatment for it. If you are already taking the necessary medication, I hope it helps.
If possible, try to get your daughter alone for a bit when she is in the house. I presume on the nights that she is there, she spends some of the time alone in her bedroom? You could go upstairs, knock on the door and ask if you could have a chat. It's important that any conversation you have with her is done from a place of calmness, so I would advise making sure that you are in as calm a headspace as possible before doing so.
I would suggest framing the situation as an issue of mutual respect for each other. You could begin by telling your daughter outright that you respect the fact that she has a new boyfriend and you're happy for her that she is so happy and excited. Make it obvious that you respect her as an individual and understand why, at this age, and in these circumstances, she is enjoying having an independent life away from her parent.
(I'm not saying that you don't already respect these needs of hers, just saying that it may help to literally spell it out to your daughter if you haven't said so already.)
Hopefully beginning with such an approach might might make your daughter more receptive to listening and taking on board the rest of what you have to say. You could bring up the "fuck off" comment, but I would advise not to do so as a telling-off. You could say something like, "I respect the fact that you apologised for it. However, it was rather hurtful in the moment and I think we all need to remember to treat each other with respect." You could outline what you see that as entailing - refraining from swearing at you, making some effort to clean up any mess that she personally makes.
If you frame it as both of you needing to make some concessions (regardless of whether you realistically need to) and communicate it as an issue about mutual behaviour and attitudes all around, rather than just your daughter's, then there's a possibility that your daughter may be more receptive to what you're saying and not interpret it as an attack upon herself.