Ahh, I often feel like I don't deserve friends; like I don't deserve squat. But of course, this is not true! Everyone deserves at least a few friends. softshock11 is right, it's not like you meant those friendships not to work on purpose. Things just happen. But I believe that there is no such thing as too late to make friends; it's only too late when you have truly given up on the effort and given up on yourself.
Try to find what you are good at, join a club you like, find a common interest with people. You could make a lot of friends that way. I know it is terribly difficult for me to maintain friendships, but I have learned to try, despite past failures. Because if I am standing at the bottom, and I am trying, the only way I can go is up, right? Same is true for you. It may seem pointless because you have always had a hard time with it, but the more you practice, the more you will eventually get better. You could find someone you want to talk to, and focus on becoming their friend. Maybe talk to them a little each day, and you might have a friend soon. Even if you fail, keep trying, because the emptiness can't go away if you stop trying; however, it will go away if you do work at making friends.
Good luck... I am a freshman in college, and I feel isolated because I had to leave all my highschool friends, and even though I am making friends in college, I still feel unbelievably lonely at times because I feel like I barely get to see them in a school so big with so many people. It sucks. But I am still trying to be friendly and talk a little every day. =]