Why do i sweat so much ?

I am assuming I have a sweating problem. I don't approximately know when it started but I'm going to take a guess which it going to be last year. I am a 14 year old girl who is currently in sports. I would sweat in the freezing cold winter wearing a short sleved shirt in school and I would sweat so much I would be too embarrassed to even raise my hand because my armpits would literally be soaked in the winter! I would always tell my parents and they would show no concern about it like it wasn't a really big deal and they said that a lot of ppl sweat a lot. They don't understand that it really does lower my self esteem because I can't feel the same as a regular girl. I was in softball practice one day and it was only like 5 minutes into the practice and I was sweating like a dog. We had just started doing stretcing and we were doing the over hand stretched and I hesitated and I looked at every on else and they had not sweated one bit. Can some one tell me what is wrong with me or tell me how to stop this because it is very embarrassing and annoying. Please help. I was also wondering if birth control stops sweating or at least reduces it.