10 pounds can be quite a lot for some, it depends on your size and strength. The fact that your young and can build strenght easier than an older person, you might be ok. My suggestion is to find someone close by that has a bow in that weight range and try it first. Over bowing can cause all kinds of problems. If you do decide to go 45# don't just start off shooting it. Shoot your 35# bow and just pull the 45# bow for several weeks until if is comfortable. Pull and hold as many times as comfortable, rest a few and do another rep. do three or four reps every other day. and in a couple weeks you should have built the strength to handle the weight.
Bob