I feel disgusting when I eat

[Cxoxo-1234]

I'm 16 years old and have always struggled with my weight I can go from being a healthy weight to being overweight in a matter of weeks ,right now I think I'm at my biggest but I just don't understand why as I hardly eat ? I have my "on days" which is when I will eat but then my "off days"is when I don't , I'm at the gym everyday and I'm addicted to fitness now since I started a few months ago ,food makes me feel sick and I don't know how to deal with it , my family don't know as I don't want to worry them they don't realise I'm not eating because when they ask what I want to eat I just say I've already ate , I hate lying to them but I just can't bring myself to tell them I don't know how to get help but I sure enough need it , i hate this