Can you tell me more about how you left, Bemorepanda?
I stayed, he left. My flat.
I simply detached - got to the end, and got there in my head. He went to visit his Mum across town and called me to bitch about something (actually to tell me I needed to work on my attitude!!!) and I said "This relationship is over. You need to move out when you drop the kids off". End of. I refused to discuss anything on the basis that it would simply be all about his rage. I got very cold and disconnected. Detachment can be so WONDERFUL and empowering!!!
I'd been trying to discuss things for years and got no where, so there was nothing to discuss (unless he was prepared to be completely open and honest which he wasn't). There is nothing to argue about - nothing at all. I was no longer prepared to be a vent point for his rage and fucked up personality. Not my circus, not my monkeys.
He brought the DC home, stropped around getting some of his stuff together and went to his Mums. No longer my problem. Hooray!
He continued to be unpleasant, and I just ignored him, refused to speak to him (as he would try and abuse me). Restricted communications to emails. Initially I tried to be reasonable/nice, and let him access the flat to see the kids (on the days he collected them from school) and he took this as an opportunity to abuse me, so I took his keys away, and told him he couldn't come into the flat. Once he learnt to be more kind and reasonable, I got a bit softer and easier. He now hasn't been abusive for about 2 years. But I expect it will happen again at some point. When it does, I will cut him off from me (not DC but me) entirely again.
You are going to find things improve dramatically in yourself as soon as you get this dead weight of a person out of your home.