Ill Health, need advice please.?

Im 17 years old and recently took a severe allergic reaction to morphine tablets that i was on and by the time that the doctors worked out the problem, i was unable to swallow and my weight went from a healthy 7 and a half to 8 stone down to 5 and a half stone. I was eventually admitted to hospital and fed through a nasal gastric tube for a week and a half before then being sent home. I was doing really well and got my weight up to 6 stone 3lbs, but then took a bug and havent been right since. I have no appetite and barely eat a thing. I hate it but just can't do anything about it. All i eat in a day is a small 14g packet of raisins ( 40 calories) and a packet of snack a jacks ( 89 calories), and i eat them at night, usually around 3am. The thing is i hate being the weight i am and i hate the way my body looks, but i have no idea what to do about it as i have lost all faith in doctors as they almost killed me and the experience i went through in the hospital was so bad that i couldnt go through it again. I know how ill i am and i know i need to do something about it, but i feel so lost and confused that i just have no idea what is going on. I am really scared. At the moment i am 33kgs (5 stone 3lbs), I am 17 years old and am 164cm (5ft 4 inches) in height. Can anyone help me? Thanks