This is a real problem. People need to know that YOU ARE LOVED. There is only one of you, that's why you matter. You are you. Always remember that. Stars can't shine without darkness. People can't glow if they say they can't. You aren’t alone.
I read this on @HPGirl11's profile, and I think I cried a bit. I think things about myself that others say aren't true, but I never believe them. This doesn't exactly end these thoughts, for me, or others, but it def helps.