try taking a few days off drums. sometimes when i get stuck in a rut i just lay the sticks down, and when i come back, im rejuvenated and feeling better than ever.
also, check out the article on this site for double bass.
heres the link:
Double Bass Speed and Control
i dont know exactly how your problems are, so this is the best advice i can give judging by your thread title. in the end it just comes down to practice to make perfection.