I'm new here so hello all. It's taken quite a bit of courage to do this if I'm honest...
Well this is likely to be a very long story but without the back history it's pointless me asking for opinions or advice. I'll try and keep it as short as possible. And I thank any of you in advance for a) taking the time to read and b) any words of wisdom or advice you can offer 
So I'm a single mum of 3, dd aged 20 has her own home since this year. Ds1 just turned 18, and Ds2 aged 11. Dad left the family home around 10 years ago and I have never had a partner since.
We have recently moved to a smaller property due to dd moving out (cheaper rent, smaller for me to manage as I have disabilities, and nearer amenities and school for ds2.
Right here's the long bit ds1 has always been difficult.... Since he was about 3 years old he's been angry, violent, and abusive. When he started school he wa referred to camhs who had him on their books for 8 years or so but did absolutely nothing, no diagnosis, no support offered.. Nada.
This behaviour got worse as he got older but he also has a tendency to be very jekyll and Hyde (at home be thoroughly evil, but elsewhere be pleasant as punch) and this continues to this day.
In the past he has assaulted me, threatened me, verbally abused me, psychologically damaged me and controlled every aspect of my life. He's threatened me with weopans, thrown hot cups of tea at me and all sorts and despite asking for help from children's services I was told I was doing a fantastic job of dealing with him and little help was offered.
Over the years the violent outbursts became less, but the verbal and psychological abuse worsened. I was physically abused by a sibling as a child and if I ever said anything to him about his behaviour he would say things like no wonder she used to best you, you deserved it, you're a psycho, you're toxic and you don't deserve to have a family etc. Then it would be things like.. No wonder dad left, no man in their right mind wants to be with you, I can see why he hit you and cheated on you. My own father left my mother when I was 17 and he tells me that was my fault too.
Now this isn't me blowing my own trumpet or making out I'm Mary Poppins but I can genuinely say I am one of the most caring soft hearted people who would do anything for anyone. I hate conflict, and I do my best to be the nicest person I can be. I've sacrificed my life for my children and have provided for and loved them unconditionally single handedly for the best part of 20 years.
He makes me believe these things and I am now in a place where I hate myself. I doubt my own judgement all the time and don't know who I am anymore.
He bunked secondary school all the time, started a college course and bunked that and would never get a job or contribute. He's lazy and sleeps all day and is awake all night keeping the rest of the house awake. There were some weeks I was surving on as little as 1hr sleep a day. He would go out of an evening and I'd ask on school night because of ds2 he was home by 11pm. Weekends he could do what he wanted. But he would stroll in the door at 2/3am and wake everyone. He'd leave a mess everywhere and would never clean up after himself. He would also smear faeces around the bath and leave it for me to clean (this still happens) he steals people's stuff and helps himself to whatever regardless of who it belongs to.
Anyway after years and years of his horrible nasty behaviour towards me, his siblings and my own mother I have been offered no support at all. Last December he assaulted me and I reported it to the police because I needed an end to it. We didn't see him all over Xmas or new year and he'd made a life with his gf and her family and I kind of felt relief that he'd moved on.
In January he came back and told me his gf was pregnant and he just manipulated his way back into our home (even though he hadn't fully moved out) he uses sob so tries to make people feel sorry for him and like a fool because Iove him regardless I fall for it every time. And took him back in.
Well, because his sister moved out I spoke to him about moving to a smaller property and asked him if he needed a room or was going elsewhere... He said yes he required a room still so I found a place big enough for me ds1 and ds2.
We've only been here 8 weeks and he's spent 6 nights here. Of those 6 nights he has absolutely trashed the house with mess, left faeces in the bath, woken me through the night on every occasion and not been very pleasant at all. He's messaged several times saying I'll be home at such and such a time so I put him up a dinner and he never shows with no explanation or anything. Then when I do see him and politely say look pls message in future if your not going to be back because I am wasting food and money etc, and he just gets abusive or refuses to talk to me.
The baby has been born now and I told him baby and gf could stay 2 nights with him preferably Fri and Sat so it doesn't disturb ds2 sleeping on school nights. We'll they've stayed twice and they are lazy they sleep all day and leave me to sort baby.. I cook food they don't even wash up or clean their mess. It was his birthday not long ago and they left mess all in the lounge and promised to clean it up in morning but they slept through til 1pm in the afternoon and because I had workmen coming out at 8am I had to get on and do it myself. I then found mountains of sick in the bathroom which took over an hour to clean.
Anyway, skip a little further forward...
Sobthe reason I ask him to spend a certain amount of nights at home is because I took the property specifically so we had space for all and I am on full benefits at the moment because of being out of work temporarily through a newly aqquired disability and I also fractured my pelvis which has changed my mobility. I cannot claim the full amount I am supposed to because its reduced as I have a non dependant registered as living here... But ultimately he's not living here (only when it suits him) he also contributes nothing to the household. He has recently started a job and said he will contribute when he starts getting paid, but I know darn well mineybwill be withheld if I don't let him get his own way etc, it's another avenue to manipulate and control.
Anyway yesterday I tried making him aware of the ful situation and it got very heated. He won't talk to me about anything and just does what he wants when he wants and I am getting so annoyed with it. He woke me twice early hours of Monday morning at 3am when he came in and at 6am when he went for a bath and I later found faeces all over the place in there. It's making life a misery and I can't go on and I've told him this.
He got very verbal and angry yesterday when I confronted him about it all. And I asked for his door key and told him not to come back. I am sick of living in fear never being able to say anything or lay any house rules and generally being dictated to by an 18 year old. It's making my 11 year old miserable too. Well anyway yesterday he told me I was disgusting and he threatened me twice, tried physically taking my phone off me when I told him I was going to call the police and verbally abused me. He then told me I was to stay away from him and "his" family otherwise he would get me "sorted out"
I am now sat here today feeling like I'm the bad guy, feeling guilty that I asked him to leave but I have had an absolute gutful of it and I cannot stand the thought of spending any more of my life living like this. I have endured 15 years of this and am at the end of my tether. What would others do in this situation? I potentially want him to live elsewhere for the safety and sanity of myself and ds2. But also I feel terribly guilty throwing him out ... Please help 