I think I have an eating disorder, and I think its affecting my growth?

I've been doing this since probably 5th grade, and im going into 8th grade now. basically i'll be really careful about what I eat, counting calories and over exercising. and then a few days later, I'll go totally overboard and load up on junk food. then i'll feel totally guilty and starve myself. It feels like i've been doing this for so long that it would seem weird not to tighten my abs to avoid having a slight pooch, or weird not to look in the window or mirror everywhere i go, wondering if i look fat. but now I feel like my eating habits are stunting my growth because im not getting the nutrients i need. Help me please??!