From what you describe I agree that it sounds like you are trying to do too much too quickly; this means that not only is your body not ready to catch up with your brain yet, but also the body tends to tense up when you push it harder than it's ready to go. Hence erratic playing.
That said I would also look at a couple of other things that might help. Whether you're playing slow or fast it helps if you have the kit set up in a way that is most efficient for you.
As a general rule, a loose batter head on the bass drum will offer less rebound for the beater and a tight head offers more rebound. Think how quickly and how high your stick bounces off your snare drum head [assuming it's tuned reasonably high]. If you want to be getting a nice bounce off your bass drum, trying tuning it up a little - obviously this will depend on how high you want the pitch of the drum to be.
Secondly, have a look at your bass drum pedal. As with the sticks, it's the pedals' job to do a lot of the work for you: it's a machine and that machine may require a little calibration. A tight spring will snap the beater back quicker but be harder work for you to press down on. Try experimenting with the spring and any other adjustments you can make (pedal board angle, beater angle, beater height etc.). With the spring, try setting it half way between maximum and minimum tension - if you see my meaning - and fine tune it from there according to how much tighter or looser you want it. You may need to play around until you find the sweet spot.
However these are the secondary considerations to the main piece of advice which is practice. If you want to build up your bass pedal foot try focusing on that separately from your main practice. For example, if you set a metronome at 60bpm then trying playing 1/4 notes just on the bass drum for 2 or 3 minutes. Non-stop, landing the beater dead on every click. Now try 1/8th notes at the same tempo for another couple of minutes. Then 1/16th notes. If you feel any tension or cramp - stop immediately.
That exercise should not be too difficult provided you relax and approach it at your own pace. If you can't manage 2 minutes non stop - just do 1 minute. But do it every day until it seems like 2nd nature. Then over time you could try doing it for longer and at faster tempos.
Good luck and have fun.