lose the belly, not the booty

I’m 17 years old (18 in 3 months).. 5 foot 3 & african american. my whole life I’ve been very thin.. too thin in my oppinion.. teased & what not. now out of nowhere I’ve started to gain weight. I’m 127 pounds which may not seem like a lot to you but this time last year I was about 105. I haven’t starting eating more nor have I become any less active. my face is pudgier (no me gusta) I have this annoying back fat that shouldn’t be there & worst of all this STOMACH. [still flat chested.. thank god for the push up bra] I will say that my legs are thicker & I get comments about having a booty that I never got before. this part I like. but as for the other stuff… oh no, I need to lose weight. when I tell this to my friends they call me crazy & say I’m skinny but this is only because I suck my stomach in 24/7 ! lol. I want to LOSE this belly, back, and face fat & I’m told the best way to do this cardio. (start jogging) but I’m afraid I’d lose my bottom half that I’ve come to love so much. is this just a part of puberty even though studies show I’m done growing/changing ? is cardio really the best answer ? will I lose my thighs & butt aswell ? any advice at all will help. [=