Wow. If he wont have sex with you then the problem is NOT in your head. It's real, & you are right to address it.
You have been married 2 years & have only made love once, you pleasure him I'm assuming with the ways that are not full on sex, hands & mouth. So basicly you are his slave. If you want to be in a sub position with him then embrace it. But if this is a problem like you say it is you need to lay down the law right away.
He dosn't do you, you don't do him. Sure this can develop into a war of Attrition but it's already so bad in my eyes if it comes to that, leave. You deserve better. If you can't leave you need to gain some of your selfrespect back. Being his sexual slave is nt a way to instill hope & respect. If you have a weight problem, he knew this when you were dating. Did he do you then?
There are a lot more questions I want to ask but I hope you start with speaking up tp him & telling him that this is hurting your bady image, your heart, & your soul, & you wont stand for it anymore. If he is willing to go to councling then thats a great first step & you can strt working on some of thesexual issues. If he can get off & your getting him off, he should be returning the favor. If he refuses it's a control game. See the last post I made in this thread & ask yourself if thats whats happining to you.
You are a person, with a heart & soul, just because you are fat, at the moment I might add, dosn't mean you don't deserve respect & an orgasim now & again.