Wow. You've described a relationship that has conditioned you into becoming a carer for this adult man - by him and his family, by your parents' relationship and your family.
I am so sorry OP, I know you don't need or want my pity, but it does make me feel sad that an intelligent, capable woman like you has been reduced to such a small and mean relationship, with a man who does not and short of a miracle, will never likely be an equal partner.
Your long post about what he would like or expect from your marriage (all the cooking, cleaning and expectations of sex) was really upsetting to read.
Because you write all about what he wants, what he's expecting from you with no thought from him for what you want.
Of course he was devastated when you previously broke up - he lost his girlfriend/ housekeeper/ pick-up-after-him carer. I would be very upset too if the person I relied upon to do everything for me left me.
I'm a SAHM and have been for +10 years. The things you say your SIL does for your brother, because she's also a SAHM does not happen in my household. I have never waited on my husband hand and foot, he married the wrong person if he thought that was going to be the deal. I don't bring in any money to the relationship, but I do bring myself and I'm beyond any ££ value! The housework and cooking is mainly down to me, but he's not beyond vacuuming or cooking etc. when it's required. My DH values the housework and child raising that I do.
It really sounds like you need to learn to value yourself, otherwise you will end up like your mother (she hasn't had a happy marriage, now hates men, you wish she had left your father). You also don't want your daughter to grow up expecting so little for herself, do you?
I'm sorry that you're in this crap relationship, don't doubt yourself, you deserve better than this man