I feel like there's something wrong with me, please help?

Im 13, 5'1, and around 80 pounds. Ive been depressed for about 3-4 years. Ive had a few traumatic experiences. And I feel like im on the verge of an eating disorder. Im very mature for my age. Ive dealt with alot of rejection and am very insecure sometimes. I am very moody and have thought that I was bipolar or had BDP. I often have feelings of nothingness or emptiness. And im not sure what to do.