The title is an understatement. I've been trying for months, and I can't for the life of me play bass drum 16th notes while playing 8th notes on the hi-hat. I can play snare 16th notes and hi-hat 8th notes just fine, but if I try to play the same thing on the bass drum, I end up hitting the hi-hat irregularly. Basically, whenever I hit the bass drum, my body involuntarily also hits the hi-hat. If I "speed up" my hi-hat to 16th notes, I can easily play bass drum 16th notes.
What should I do? I feel like this problem is really holding me back from getting better overall, and I feel like the longer I ignore this problem, the more difficult it will be to break.
I would really like answers more substantial than "just practice". If that's the bottom line, then so be it, but I'll be more inclined to accept an answer with some specific advice, such as a particular song or beat or technique I can try.