transistor help

As it is I have proporcional control over the motor in one direction , the otehr direction deosnt work ,
I just hook the old servo board onto the RC Rx and control it with theTx.

the plan (other than learnign stuff and passing the time of day) is to make a speed controller for a brushed motor,
i know the mosfet I have used is massivly over specced for the job, but I have a few of them lying around, and can get a few more, they are in an old battery charger we use at work , and we have a few fried ones,

Looking at an h bridge, it uses four transistors, is that neccesary? i would have imagined that two would be good enough,

servo schem.png