UBER FPS DROPS WHILE MOVING MY MOUSE

how i hate cs........
so, when im moving my mouse im getting 5-10 fps, but when im not moving my mouse i have still 100fps!!! =/, i found on google that is because of HZ in my mouse (im playing with 1000), i changed it to 125hz and fps drops are less like 70-80 but i still can't play kz/lj with these fps. please help me and remember that i have fps drops ONLY when im moving my mouse! :(