You're just being hypercritical of yourself. Being skinny is like the least important thing in the world anyway, but just because you've been skinnier in the past, doesn't mean that you're not skinny now, or that you looked "better". He chose you based on how you look now, not how you have looked or could look. You're obviously gorgeous!
it also doesnt help that he has a six pack and a great body and could be with someone hotter..i dont doubt that he’s attracted to me or that he doesnt like me..i just think our relationship would be better if i were better looking idfk im still new to relationships so i know a lot of this is normal thinking, not that that justifies it lol. it’s still bad to think that way.