How do i escape being "Skinny-Fat"!!?

Im 15 now and i used to be 155 lbs and 5''3 i stopped drinking soda,junk food, and I started eating 6 small meals throughout the day instead of eating alot like i did when i was 170. now its been like 5 months and I weigh 115 lbs and im like 5''4 or 5''3... My arms are skinny and so are my legs but i have a BIG sttomatch and smaller man than i used to have.. Im all flabby in my stomatch area.. what should i do?? should i try to get muscle?? or do alot of cardio?? but if i do cardio will i lose muscle and if i do cardio and lose the masive belly fat and man s would i be like 80 lbs or somethin aand im like 5''3??? what do i doooooo?????? helpPP?????????!!!!!!!