dude im in the same position as you but even worse lol. all i play is piano and guitar, and i suck at piano all i can do is slowly compose melodies and on guitar im nothing special.i have only played piano for liek a year and guitar 2 years haha. i dislike performing but i really like composing music, do you have to be an amazing performer to be a successful composer? ive only got a couple months left of high school and music is what interests me most and id love to compose music as a career but the reality is there are thousands of people better than me so i dont think it would be wise to go to a colelge and study music...but theres nothing else i really want to do!
also,
i know exactly what you mean about composing, ive only composed a few pieces and im also convinced i can compose lol