Do I have an eating disorder?

I started dieting a few months ago, and I've lost 55 lbs since. I lost the weight really fast obviously and I didn't eat right at all (about 600 calories a day, absolutely no fat, no exercise). I was malnourished for awhile and my hair has started to fall out and still is in the back. Recently though, I've started eating better because my mom made me and my sister said that she was really worried about me, so I got scared. But with eating healthy, I know things are good for me but I just can't eat them. I chew foods and then spit them out because I feel guilty a lot. I also get obsessed with calorie counting and get scared of even eating 1000. Recently though, I started making myself throw up. I've only done this twice but I'm scared. I don't want to hurt myself but I honestly can't help but feel guilty about what I eat. My weight is in the healthy range, my bmi is around 22, so I'm not like underweight or anything, but I think I'm still malnourished. What should I do?