I'm the exact same way. I'm going to be a junior this year, and I have yet to have a boyfriend! Don't worry about it, sure it sucks not having a date every once in a while, and not having someone to tell you you're beautiful even though you might not think so...but honestly, you're dating your friends, because they can provide a lot of the same things a boyfriend can.
I know it's hard but hang in there, try to be a little more welcoming. Try to be more vocal in your classes this year, and try being friends with more guys, this way you can meet their friends and who know, maybe you'll hit it off with one of them! It's bound to happen!! Let me know how you do, I understand 100% so I'm here if you need to vent. :)