okay lets give a little back story 

when i was 13 , being a very overweight child, i used to  get really really bad scabbing around the inside of my thighs, along with the scab on my but crack (no idea if its with the problem of being over weight)  luckily all the scabbing around my thighs went away but the scab of my butt crack never did, when i was 14 i started to get a very sensitive itchy scalp then from there on they turned into scabs, they've been here for a very long time im turning 16 and im really insecure about my self, with being overweight im loosing it slowly,  im not happy with the way i look and having scabs espeacially on my BUTT crack!i dont like they way it looks, anyone please help i have no idea whats going on and i dont trust my doctor he tends to always say its cuz of the weight is it?