REPOST: NOT ANOTEXIC. I think. How much longer can I go on with my lifestyle before I'm hospitalized? Advice?

I eat 50-400 calories a day, before purging. I hate food and I only eat it when other people make me or when other people are suspicious. I purge about 50% of the food I eat. I don't think I'm not fat, infact I'm 5' 6" and 105 lbs...I'm just afraid to gain weight. Even though I know I'm not anorexic and I don't have a problem, my best friend seems to think I do... I hide my eating habits from everyone. I run about 8 miles a week. I've had this lifestyle for 3 weeks and am still losing wieght