your muscles shouldn't shrink while on creatine. if you are trying to cut down for season, creatine may not be the best choice, especially if you "sweat out" before weighing in (God that's terrible for you). You don't want to dehydrate yourself that badly. Its just plain dangerous. Adjust your weight with your diet. If you want to drop weight, keep your water intake constant, increase protien intake, and move your diet into a safe caloric deficit. you may loose a tad bit of, but you'll cut body fat as well. Supplement your protein intake and workouts with BCAAs. As hard as it may be, eat as cleanly as possible. Eating sh*t foods will only counteract what you're trying to do.