Nothing like a night without sleep to find the ideas you need.
I think that i understood what is going on I think that the diode across the primary is a must have, cause it reduce the dV/dT transient, cause by the interruption of the current, If the diode is not there the "charged primary" will suck down electrons thru the capacitance between the drain and source charging the drain and source capacitance to up to double the supply voltage, and all this very fast. .
So i'm going to add a snubber circuit in the mosfet and across the primary, across the primary i will have a diode and some resistors, and across the drain and source there will be a capacitor and a diode with a series capacitor so we can discharge the drain source capacitance tension to change slower... I though about adding a 1nf capacitor and a diode with a 10k resistor in series...
I though a way to protect against the fuse blow too, i'm going to add a capacitor and a resistor in parallel with the fuse so if it fuses it wont destroy the mosfet again...