Young Trumpeter

I'm in high school and i had off from school the past week and so i've been practicing like a mad man, day in and day out, hours a day. at first it was great and i was loving it but now, a week later, something seems to be wrong. i have a jazz recital (NYSSMA to be exact) on friday and i've been playing through the piece a lot and recently i've noticed how soon i become fatigued. i can BARELY get through the piece (or any other practice routine such as scales or lip slurs) without tiring to the point where i can't play. i subconsciously begin to apply pressure and my style and phrasing suffer. at first i thought i was practicing my routine (long tones, lip slurs, scales) wrong and now i'm out of shape but now i'm beginning to think i've been practicing TOO much. i know it's difficult to decide on the problem without hearing me play but when do you pros decide when it's right to take a day off (and for that matter how do you approach practice in the days leading up to a gig/audition?) and what's the proper way to come back to the trumpet.

Thanks.