I'm sorry you are in so much pain. Growing up in this age is so hard. Comparing ourselves to others will certainly at some point or another make us feel bad about ourselves. Social media seems like a bit of a contest to me at times. I've deactivated facebook because I really don't want to see other people's highlights of their lives. But that is something to remember, people will show you the "good" stuff, vacations, highlights of their life, but you don't see the ugly side.
Anyhow, I know, some things you just can't change. But some things you can change. See if there is something that interests you that you could develop as an interest, for your own enjoyment and for no other reason. We need to be happy with ourselves before we try to find anyone else anyways. No relationship will work unless you can be ok being alone with yourself.
I feel like suggesting to most people with problems, to listen to Eckhart Tolle on youtube. There are many good videos, of course, just my opinion.