Life as a queer teen

I feel like I'm really behind in the romantic part of my life, and I can't tell whether that's because I'm queer or because of other reasons like my personality or appearance. 

People always tell me it's because I'm a lesbian, but many of my queer friends have been in a relationship or are still in a relationship, so I feel like that's just not true. Is that normal? Most days, I feel really sad about it and just want to know whether I'm the problem or not