I have been playing for about 6 years, and Am a senior in high school. I consider myself a pretty decent player, but one problem I have always had is that my lips will get si tired I just cant play for too long. Air starts coming out the corners of my lips, and I have to take a break for a second to recover. Its a very annoying process, and was wondering if their is anything I can do to help make my lips much stronger.

There are two ways this happens. One: your reed is the wrong size for your lips. Judging from your description, it might be too thin. try upping by at least half a size (I started having this problem on 2.5s for a while, but I switched to a three, and it stopped) If that doesn't work, your reed may also be too thick,so try going a size down.
or two:you don't practice enough. No matter how good you are, or how little practice you need for technique, you should still practice alot to 'excercise' you lips. This also happened to me, where my technique didn't need that much frequent practicing, but when I started to get lazy in my practicing, my lips died out, and I was having problems.

i put vaseline over my lips after and its ok