Hi. I am thirteen years old. I have stretch marks on my butt and thighs. I have really dark and bumpy skin on my elbows and knees. I have bumpy skin on my legs (maybe partly because of shaving, but there might be more to it), and I also have dark and bumpy skin on my armpits (also maybe due to shaving). What can I do to solve these problems? It is really hard to have fun in the warm weather with these problems. Please help if you can.