5'6" and 109....am i anorexic?

i'm 16 yrs. old, 5'6" and 109 lbs. I have been losing weight since april of last year. i was 195 lbs at that time. i haven't gotten my period in over 7 months and i have constant thoughts about food and weightloss. i have an intense fear of gaining weight.. if i gain .5 lbs, i'll freak out and restrict my intake more. would i be medically diagnosed as an anorexic at this weight?