It is totally normal during adolescence to have irregular patterns of eating. It can even be episodical with phases of high apetite and periods of scarse meals. You give very few imformation so we can make an appropiate deduction, bt what you give it does not seems anorexia.
Now the cutting issue. Selfharm is also common, it can be expressed in many ways. Other teens do excesive exercise, others bige eating, others get in to fights. You must look into your self and look for your reason to do so. If you think you can be depressed (which is also common) maybe a small trial with conductual cognitive treatment can help you.
I remmeber seeing on Imgur a post of a girl that recived by her therapist the idea of painting herself insted of cutting. She ended up doing awesome and beautiful drawings on her skin, and then she uploaded them to imgur. She recived like 5 tousand upvotes in a couple of days. I think that what she did was brave and beautiful. I will see if i can find the post. There are always other options to self harm.