Allright, I've had the same problem in the past... Before I graduated, earlier this year, I couldn't do much, other than card magic and flourishing... I had only been doing it for a couple years or so....
But, now that I find tha I am now graduated, I have more time on my hands, thus allowing me to practice much more often...(after graduation, you may actually have less time on you'r hands though) however, I am guessing you between ages 15 and 18, If you are not grade 12, then slow way down. If you are grade 12, focus on you'r grades, you just have to find things in you'r classes that draw you'r attention... I know it can be hard, especially if you feel you have "better" thngs to do, but the thing is that you have a lot of time to "catch up", as you look at it. Everone has a peek, and eventually you'll reach it.
This being said, I still haven't reached my peek, and I've been doing these things consistantly for the past couple of years... It's a hard fact to live with, but you have to be focused when you practice, not destracted, and honestly, if you lose 2 to 5 hours of practice a day, then it won't really effect you in the long run.
When you are in school, don't bring the cards, or tricks out until lunch or spare, and if you have homework, do it during spare, so you can practice steadily in the privacy of you'r home.
The more focused you'r practicing is, the more you will learn from it, don't practice at school. Perform at school, when people can watch, not during class.