here are a few tricks you may wish to try.
(1) MOSFETS love to be in parallel. This allows you to get the heat down a lot.
(2) Overdriving the control a bit on MOSFETS (50% or less) is generally safe and causes really fast response. Read the specs on you MOSFETS yours may be able to do this.
(3) Just for fun on the DC segment rather than killing the current entirely while running leave a modest few milliamperes hanging in the main drive coil at all times you are running the motor. It will drag the coil slightly but may affect current demand in the circuit a lot. This might well be worth the effort. This is a trick to prevent the collapse of the magnetic field in the coil of the DC motor. If it requires a voltage reversal, time this reversal when you are already into the next drive position some.