here is a picture of the supply voltage (used another 5V LDO) , output current and total power graph:
I circled around the places where I rotated the pot (about 1/4 of a turn) as you can see, the jumps are massive! it goes from about 200mA to about 225 then to 250 then to 500! at which point the LDO can't keep op and starts shutting down when I turn the pot down and as you can see there is a massive decrease with less than 1 turn again! from 335 to 75! I then turn it a bit more and boom! zero! after rotating it to increase the current, it jumps to full power in less than a turn again! I measured the Vref , Vgs for both fets and the the voltage shunt across both resistors and they are very well behaved. I can't give you exact measurements as I use a cheap multi meter so the numbers can be all over the place, but Vref and Vshunt were about 6mV as indicated by the multi meter (probably wrong and way off!) but they were matching which is good. Vgs for both fets was a also about high 1.7 or low 1.8V range which again is matched nicely ... I repeated the same measurements using a 12V 5A laptop charger and same story again ... I kept it at about 10.5 watts and the mosfet on the left got super hot again, while the other one stayed cold to the touch ... is it possible that the second mosfet arrived dead / died during soldering?
Edit (update):
so far I have noticed an issue:
The spacer nut I used to keep the mosfet from rocking back and forth, might have been shorting out one of the tracks (shorting source to ground), but even after lifting it up, it didn't seem to resolve the issue ... I'm not sure if this could have killed the fet or not
how can I test the fet?
the op amp might also not be able to drive the gate capacitance as others have mentioned, but I have no way of testing that right now. I have to check with an oscilloscope in uni tomorrow.