OP your situation is very similar to mine, so my heart really goes out to you in what you are currently going through. Thankfully I managed to move out with my DC a while back to escape the abusive stalemate in the family home, so am currently renting while deciding what should happen next. - I can tell you, the relief to be physically away, at last, was overwhelming.
But I am struggling to continue to afford my current renting situation. I now really need my legally agreed share of the equity in the family home asap, to get myself back on an even keel financially, but DP still lives there - and refuses to sell it or move out. By refusing to negotiate or communicate at all about the separation he doesn't want, he is therefore still managing to exert his control - hoping I think that I will soon run out of money and have to come crawling back. I think that informally agreeing how to divide assets is very risky indeed, especially if you are dealing with a controlling person with MH issues, as I am. Any solicitors here will probably confirm this from experience?
I have already started to spend money getting initial legal advice, eg. regarding potential judicial separation vs. divorce - plus a future inheritance situation - (his) - All this isn't made at all easy, cheap or simple for us to understand without paying a solicitor! And I have found to my cost that not all solicitors are equally helpful. It feels very unfair when we are already struggling to make ends meet, on top of doing the lion's share of supporting our DC with extra needs.
What I am learning is that my DP is fundamentally extremely selfish, expert at gaslighting/messing with my head/playing the victim card, under the guise of 'I love you/can't manage without you' etc etc.... with his own self-interest actually being absolutely at the forefront - ahead of both the DC's best interests and mine. It's so hard to think clearly when you are living under the same roof; and the sheer desperation just to escape this will likely make you all too ready to accept less than you are actually legally entitled to - I have felt the same. I am now coming closer to the decision that a properly-handled divorce is going to be key, and that finding a good solicitor is really important, despite the costs. I gather that if DP's behaviour continues to be deliberately obstructive and unreasonable, a judge does have the power to turn some of the costs back on to him, in some situations.
Please stay strong and try to keep a clear head, don't give in just to get away.