I swear it's almost as if I typed this myself...I am EXACTLY the same way. I have an older brother who has received numerous comments from girls because of his looks, while I get nothing. He demeaned me all my life, insulted me, etc. I try and avoid confrontation and consider myself a misanthrope because I cannot stand strangers. How I deal with it, is that I just simply continue on with my life and eventually my success will come. My brother for example may get the girls and be better looking, but he has a long list of problems to go with that. He drinks frequently, and has had an on and off again drug problem for a good chunk of his life. Also, every single relationship he has had, the girl has dumped him because of his problems. It's quite funny because here I am, a guy who will (while not being a pushover) treat a girl with respect, yet they choose my brother all the time. He is 29 years old but certainly doesn't act like it.
I use him as a mode of inspiration, because I DON'T want to end up like him. Therefore, in order for me to do that, I need to do my best in school. He never went to college and barely passed high school. I think you just need to keep your head above everything else and do what I did. I will admit that it won't be easy (as I have found out), but it can be done.