I know how you feel, but think about who other people think you are: Your nice, reliable, a good person to talk to, understanding, VERY artistic, funny, cute (Yes, I admitted it), just a great friend in general, and you are very good at cheering people up. You just have a lower self-esteem level, that is why you need to beleive in yourself and evrything you do, don´t doubt yourself, only doubt the haters.