How do i get a faster metabolism?

HI, okay i'm 16 and 5"6' and in the midst of loosing weight. i've gotten to a ledge point so i've been eating less, and drinking more water, and exercising an hour-2 hours a day switching from strength training and pilates, and cardio every other day. but i cant seem to get my metabolism up! I already have a slow one genetically, and i know gaining more muscle mass helps, but how do i build up a fast metabolism? i've heard green tea helps for some reason... Thanks :)