I'm thinking about being on AGT this year to sing but I don't know if I can bring myself to do it?

Well, if you think you have a good voice, and can muster up the courage to do it, I think you should just go for it. Why don't you try asking your family and friend's advice and ask them what they think you should do. The worst thing that can happen is that you don't make it on the show, and if you do that would be great and you'll be happy that you took the chance. Just have confidence and believe in yourself.