I NEED HELP please with a love problem/weight problem too!?

Hello my name is Mario, I am 13, I am overweight with a BMI of 27.5, I realllly like this girl, I asked her out, but she rejected me, obviously because i am fat, in Egypt (my home country) I WAS SOO SKINNY, my metabolism was SOO FAST, i was underweight, until i came to the U.S. i started getting really fat, so yea, back to the girl, shes like my bestfriend, the other day, i went to a feast, and she was txting me, to meet in the parkin lot, she talked to me, and then b4 she left she just ran up to me and hugged me, it felt really good, then i went home, i felt ashamed, I am fat, i was in the shower, thinking, what if i was skinny, and muscular, and i hugged her, wouldnt she like it, and mayb go out wit me, and i looked at myself, felt REALLY ashamed, I really need help, i got rejected so many times because of my fat, I need help, DIETING? LIFTING WEIGHTS? Starving myself? anything, just please please please please help me!! :(, pleas, thank you very much in advance ! :)