WHAT DO I DO?

I have a boyfriend and he's literally perfect. He is smart and funny and like the most handsome dude i've ever met. I'm not like him. I actually feel bad in my skin and hate to see my body in the mirror; two years ago I was recovered for ED (anorexia) and now, even If I'm not anorexic anymore, I'm still as thin as a stick. But now when we cuddle or watch Netflix I feel horny, I'd love to do something w him but I'm too scared to even take off my shirt. We've been dating for like 2 months now and I gave him a couple of handjobs. I'd also like to give him a bj, but what if he leaves me after that? I feel like there's no reason why he's still with me, I'm not even prettier than all the girls that have a crush on him. I'm just scared of this, I think I'm falling for him and if he leaves me.. well thatd be devastating...

any tips?