Holy shit I feel so bad for you. My friends are in your weight range and somewhere between 5'3-5'8. I can get away with buying certain clothes since I am basically considered the fattest one out of my group of friends(I'm half asian so I can get away with it too). They have to buy XXS and they never buy clothes online because they never get the results they want. They have to go to the store to try them on because the measurements on the website is totally off. They are all healthy, we're Asian girls. My friend who is 5'8 and 115 lb always gets comments from envious people telling her to gain weight, does she ever eat, etc.