I think for every sexual orientation, we start to believe that we have to thin to be in. The thin, attractive people on tv shows are the successful ones, while usually the chubby ones are the comic relief....I've struggled with body image my entire life. Being a straight female, I've always seen men react to the skinny women with big breasts. I'm 28 now, and just starting to see that well yeah, men find it attractive, heck, I do too lol. But there's so much more to a person than the outside. I'm chubby, and my boyfriend is very thin, but he still asked me out and fell in love with me.
I think it took the right man and the right time...I'm not where near as self-concious about my body with him. I had an ex once who would make "oof" sounds when a hot girl came on tv.....and that killed my self-esteem. Its taken awhile to build it back up, but its getting there.
I don't think you have to be thin to fit into any sexual orientation. I think you just have to find the guys who are mature enough to look past looks and see inside at who you are.
I just have to say I understand....about the whole thin vs chubby thing and not feeling wanted.