Still living together

Recently come out of a 10 year relationship and forced to still live with him. After 10 years of physical and metal abuse, doing what he wants and likes and putting his needs before my own I have lost myself along the way. We are in the process of buying our first home to which I’ve paid 20k towards. We’ve only just bought the land which he’s paying and the easiest option for me to get my money back is to apply for the build loan with him because we’re more likely to get approved. Then once approved refinance so he can give my deposit back, so he’s currently paying that and half the rent of the property we’re living in now so until the lease is up he’s asked that I stay to help. I have no family to move in with or anywhere else to go. He continues to say he will win me back but I don’t want that. I also say that to him but I feel he’s still not taking what I say seriously. There’s boundaries that’s need to be put in place and I don’t know where to start. We’ll be living together for 6 months and I don’t know how I’m going to get through this. But I do know if I were to get back with him I will never truly find out who I am.