Real, sustainable change takes a long, long time. Especially if those behaviours are deeply entrenched. I think I remember you posting under a different username the other day when you were upset about a comment he made about Tinder? And that you'd left him due to the abuse from his MH issues, but was hoping with time and therapy it would work out?
If so, ditch this guy right now. He hasn't changed, or if he has, it's so peripheral that it's not enough to be worth getting back with someone who has treated you so terribly. I imagine you are stuck in what is known as the "trauma bond" where you have had years of him treating you like shit at various junctures, and then pulling out the stops just at the point where you are going to leave or make a decision. This is called intermittent reinforcement, and deludes you into thinking the changes he professes to make are long standing and will make a difference - they won't. If you are the OP from the thread the other day, his mental health problems are far too pervasive to just be resolved within a matter of months.
Put it this way - I left my ex DP (who I have a DS with) last year. He got very swiftly into a new relationship where he is now living with new girlfriend (of 5 months, with her two kids) and has accelerated their relationship at the speed of light. I spent many hours/days/weeks crying - surely he must have changed, I was the problem all along (like he constantly told me), he's going to be wonderfully happy etc - nobody would go out with a man as shitty as the one I saw, right? Guess what - my ex is still, despite being happy and content, abusing me, intimidating me, threatening me via email (the only place he can contact me) because I'm trying to make a very simple, reasonable change to something regarding our DS. All my emails have been polite, informative, factual - I grey rock him, and show absolutely no emotion whatsoever. But he continues to try and control me, all the while accusing me of being controlling, abusive, manipulative, threatening social services and the police etc. The things that I disliked enough about him to leave, the temper and anger and disrespect - I can still see them all.