Okay so you are lesbian, or a gay male? I remember reading that for women it can shift back and forth, they can be gay for some period of their lives, then switch back to being straight, but for men they either are gay or are not gay and there's never any switching.
Is separation not possible? It would probably be easier on the kids if you simply left him, if that's possible where you live; I know women don't have the option in a lot of places.
But, it could just be your husband in particular, esp. if he's basically raping you all the time, not men in general.
Dunno how you would feel about this, but typically it's a man's dream to have multiple women in the bedroom. That could give you maybe some distance from sex with your husband, give you some womanliness that you've been craving it sounds like, win/win. It gives you pretense to find a woman you like, of course she'd have to be bi, then you're basically giving your husband the green light to have intercourse with a different woman which is usually pretty hard to pass up, while you get to focus on the woman. Just a thought.
As for acceptance, I'm working on that part myself, so I'm not really sure. For me, I think I'm just going to get really pissed off and drink the last drink of drinks in an angry gulp like "Fuck you," to the people who betrayed me, and to my dad who raped me, in particular. If your reason is also bitterness and anger, maybe that's how you can gain acceptance. As a final "Fuck you" to the people who abused you.
Also if your BMI is 18 that's not going to help. You need to eat more. I'd recommend the liquid calorie drinks and a multivitamin. Even if it doesn't help you feel better, it'll give you more strength to do what needs to be done anyway.