Been there and done that, and a friend of mine ended up 5 minutes from death from it, it's a road to ruin.
It took me years to get in anyway better in including 4 hospital stays, a lot of pain (both physical and mental), it affected my studies, my friendships, relationships and family, everything really.
Where do you stop? Will you ever be happy with your shape (very unlikely) or will you just end up keeping on going?
It does horrendous things to your body, the effects of starving yourself may still appear and come back to haunt you years down the line.
It also changes your feelings towards your body and food with often long lasting implications. Never let it get on top of you, if you get that far, you'll never get rid of it, just lern how to try and control it more than it controls you.
It can also become an addition which takes you over so that however much you thing you might be controlling it that's very far from the truth.
You think being thin will make you happy? The only think that will do that it letting yourself be happy with the way you are, learning to like and respect yourself.
Take the control back now hon, it's really not worth it, x