We've had a nice day, all in all, but when DS is feeling stressed, it's a 24/7 job until we are in the house (he calms down in the house - and please don't anyone tell me I should just let him stay in the house as it's simply not good for his mental health or his socialisation) so when we ot in, yeah, I did the minimum and then relaxed.
I so identify. Believe me, I do.
If he is under I think 7, there is a course called Early Bird Plus which is really helpful - NAS run it. Have you been on it? It's very useful in itself, but you also get to meet other parents in the same boat. It can be really good as a means of finding support.
The thing is, to all intents and purposes you're a single parent. You just have an angry, belittling, accusatory bully in your home undermining you and creating more work, too.
He won't alter this situation for you because it probably suits him. He can be lazy and he has a human punchbag, emotionally. If you don't say to him that his shit ends or he leaves, he won't change. Even then there is no guarantee but it is the only option you have.
I agree that Women's Aid would help.
You do know that child support is not counted when they calculate benefits? If you look on www.entitledto.com I think it is (correct me someone if that isn't right) you can find out how much you'd get, and then use the child support calculator to work out how much he would have to pay you. You also have a strong case I would suspect for spousal support because you have a disabled child which impacts earning potential.
Has he a salaried job - is it reasonably well paid? Pension? Is the house rented or mortgaged, and if the latter, do you know how much equity is in it? All those are family assets of the marriage, not just his. I suspect you are not treated as though that is the case, but it is.
I'm not saying you need to act on any of that information. I'm just saying that you sound as though you feel trapped... and you aren't. You have a lot more power in the relationship than he is allowing you to feel.