Help no friends no life .**** all?

i have not been to a party in two years had no friends in two years i have no idea why people don't like me i try really hard to be nice i am not a loud person ( i used to be tho) i am really quiet i use to be a dancer and got hurt and can no longer dance i sing really well and play a few instruments i sing on stage but fell sick a few month ago and have not been on stage and since thats the only place i am happy i an screwed i am so depressed ... cut myself