I feel like such a failure?

Hey, for the past year I kinda feel kinda shitty. When I was younger I was very sociable and loved making people laugh and I was a pretty outgoing person. Now ( I'm 16 ) I'm scared to say anything because people started being really mean to me ( no idea why ) a few years ago. I have only something like 10 friends and only 2 close ones where they both don't even spend time with me anymore because they are in a different school and party all the time. I can't even pride myself on being smart. I get average grades at a hard school. Where some people don't study and do really well, I don't study and I do poorly. I do things the day before because I get really stressed out. I'll probably graduate with a 82% avg. The only thing I love is computers and I don't do anything with friends/sports except tennis/badminton/taekwondo. I'm such a shy little **** and I hate when other people talk about how much fun they had at a party/get together because I don't get invite to anything. I pretend not to like those things but I actually genuinely like having fun with people. I just... can't get comfortable with people anymore. Also, I'm so bad at talking to girls now. Two years ago I had problems keeping the girls away and now I don't even bother with them. If they are attractive, it makes me feel really awkward and I just try to avoid situations like that. I hate that I can't just enjoy life again like I did when I was younger but have to watch things p before my eyes. This time of my life is supposed to be the most fun, so why the freaking hell am I playing video games. Someone at my school parties all the time, super popular, pretty, involved in sports/activities and has highest grades in school. What the hell is my life worth if there are people like that.