Oh my goodness, I really do know how you feel.
A few things, I'm sure you've probably heard before, but you have to know that that the 'perfect weight' will never come. You will always be telling yourself that you're almost there. Please don't let yourself fall and farther into that dangerous trap.
And the control thing, I know what that is like too. But you also have to realize that the fact that you can't make yourself get on a regular eating schedule means that it is no longer in your control (I was the exact same way).
But most importantly, I understand the hospital threat. When I was still struggling with bullimia, my T told me the same thing, and I hated her for it. I hated it, because she was right, and I was stubborn.
But you also have to know that you have not reached the 'point of no return'. You CAN turn around now. It won't be easy...but if you wait longer, it will only get harder. So know that you CAN do it!! I believe in you, mija!!
And when you walk down that graduation isle, you'll feel even more proud because you made it!

I'm here for you if you ever want to pm me, dear.