I give up

I'm 20. I've never had a girlfriend. There have been girls that wanted to be with me but never told me (I found out from their friends) Then, there have been girls that wanted to be with me but I wasn't attracted to them, at all. Last but not least, there have been girls that I had crushes on, asked out and got turned down. There was even a girl I fell in love with that turned me down. Counting all of these things, there aren't many positives. I'm a positive person but this seems hopeless.