I am 13 and I would really like to try new foods but i am terrified! I don't know what to do.?

I would love to try new foods but I am absolutely terrified! I am unhealthy and want to change the way i am! Ive had enough now! All i eat is chicken nuggets and chips basically and junk foods. I don't eat loads of it, just once a day. I just can't bring myself to try new food. People don't understand how hard it is for me! If anyone knows anything and think they could help me please! Because its coming to the point where its getting ridiculous! I really need help! Thanks. I refuse to try new food, its as if im hypnotised or something!