You may think you are so different than everyone else, but the truth is all of your peers are going through the same thing. Its basically all due to a loss of self confidence and self esteem. If you liked yourself more these issued would still exist, but they would be more manageable and you could be like you used to be ... more bubbly and out going.
Puberty is tough because all the new hormones not only screw with your body, they screw with your brain and make you think differently, often making you, your own worst critic. If you stop thinking about what you are doing wrong, you will be able to do more and have more fun. But I understand that is easier said than done. If you don't figure out your way during puberty, you certainly will when its over.