I feel really crap about myself and fat?

Ohk so I feel so horrible and fat, I've put on a lot of weight recently because I'm on study leave and I just non-stop snack. My parents have started to call me "fatty" and make snide comments all the time. I know its incredibly stupid etc etc but I've tried to make myself vomit. I can't do it. All that comes out is spit. So i feel crap about myself, I can;'t stop my constant snack cravings and argggghhhhh. Need help. :)