How to increase torque in a BLDC motor
Torque = current and 150A isn't enough, so...
Gear down to the prop.
Sanity check : a 5HP Seagull Silver Century drives its 11 inch prop at about 1000rpm, which you would reach with only 3V on your motor direct drive. If you're trying to run this thing at 12V that's about 4000rpm, and power required varies as the cube of speed (torque as the square of speed) so you'd need 16x the torque and 64x the power of that motor to drive the prop.
Go back to the physics; plot the power and torque required vs speed for the diameter and pitch of your prop. Equations are easily found.
Also understand the relationship between speed and voltage, and the implications of that for torque and current, for your motor.
Then decide on the correct gearing to match your motor to your propellor at the speed and power you want.
At 1:1 gearing you'll find you can only drive a tiny prop absurdly fast, producing very little thrust.