Hi, thing is...you're 15 and no one feels particulary awesome at 15. Growing up is tough and everyone goes through this at some stage. Do things that make you feel happy, see someone to talk to or talk to your family if you can, get some exercise, read some interesting books or magazines, do some art work, take photos, do some acting classes, go to the movies, write in a journal, volunteer helping other people or animals, watch some bad reality tv and have a laugh. Never give up on yourself because you will get through this and look back and laugh.
I'm writing this to you because I used to get depressed about myself too. I was a chubby teen, didn't have a boyfriend until about 20 and felt pretty down on my looks. But I grew up, my looks changed and majority of girls who teased me at school now, look pretty average. But that's not the main reason I'm writing to you - I'm now 27 and have been going through a HUGE health crisis for the last 9 months. Once something like your health fails you begin to realise how much you took for granted - enjoy life because you never know when it can change. I used to worry about silly things (not saying what you're going through is silly though) and now I'd give anything to worry about my weight (which I used to all the time)etc...
You're a great actor - there you go...that's awesome! Do you know that people don't see your faults because you're your worst critic? Everyone is. People are more worried about themselves most of the time so don't get too down.
You WILL get through this tough time and don't kill yourself because people will miss you very much. You might not think you're important but you are....
Stick with life because I promise you that things will change for you and you'll be stronger for it and able to sympathise with people who are going through hard times as well. Lots of love, liz