These notes may help. Things I learnt after blowing a couple of dozen FETs. Have a fast current limiter - that can interrupt the duty cycle. Snubbers are essential.
L is all the stray induction, a little number.
The output capacitance of the FET helps here though. Another implication of the above is to keep wire lengths short. Make the design as compact as possible. Resistors in the snubbers and especially any low value resistor used for current sensing must be low inductance types. Wire wound implies a coil.