I'm sorry that you're struggling with this, but you said it yourself: you know that your friend is trying to help you and that you don't want to be in and out of the hospital all your life. For one thing, eating healthy foods will definitely make you feel better than junk food. Also, maybe you could talk to your friend to readjust the goals to where you start with smaller portions and work your way up to full meals. Sometimes its easier to climb a mountain if you just focus on one footstep at a time.

I hope this helps and remember to stay strong! You are beautiful and you have people who care about you!