I stripped all 4 motor screw holes by crashing my quad, now even applying loctite doesn't last long, the screws don't stay long and just drop after a few flights. 
is there any fixes?

are the threads long enough to grab enough threads on your motors?

You can try Heli coil and retap. Or just mount your motor with ziptie.

If none of these options work, then you probably have to replace it.

I used small solid wire stuck through hole twisted together and hot glued it!
But my advice, Don't put all 4 screws in next time so you are always left with 2 haha

Re-thread with a 3.5mm tap and use 3.5mm machine screws. Take care not to get into the windings. You can grind the usual tapper tap into a bottoming tap which will allow you to thread deeper. Or disassemble the motor do do the threading. Make sure your screws are as long as possible without touching the windings.

I know a lot of people are suggesting re threading the motors but i would recommend you to just get new motors.

This will be much betting in the long run & save you having different size screws on your quad.

Hope this helps