Okay, this is like you embechure(however u spell it) and if you have been playing like this your hole life, do not change it. If you change this, it could mess you up completely. So my suggestion is, if you want to have your trumpet up more, you're going to have to lift your head up some also. Thats the best advice i can give you, and trust me, take it.

It is not ment for everyone to play straight, it might have something to do with your teeth. If you have a little bit of an overbite , then you are supposed to play down. And the opposite if you have an underbite. I wouldn't worry too much about it, unless your in marching band.