I have no idea what is happening to me

For about a month now I have been really restricting what I eat, it's like every time I have to eat I spend ages fiddling with the food and taking tiny bites. I'm constantly jigging my legs up and down to help me lose weight and I weigh myself every day (I've lost just over a stone). I've been avoiding cheese and chips and other fatty foods. Whenever my mum want take out I nearly break down crying and I have no idea what is happening.

I feel like my body is constantly fat and that the only solution is not eating. Every time I try to convince myself to go get a snack of some kind I just stand staring at the cupboard with my brain telling me not to. It's started to escalate as well, I nearly purged earlier because my mum made me eat a Pizza Hut pizza, no weight is good enough, I nearly faint trying to walk across a room. I'm scared and I don't know what's going on. I'm trying to recover from depression and now this. I don't know what to do. Please help.