Controlling MOSFET and LED from same PWM output
The MOSFET takes no significant current from the output pin and the 2k2 in series with the LED will not pull the voltage down. Q2 should be a digital type (turn on 5V). The 10K could be lowered to discharge the gate-source charge more quickly and I would add a (snubber) diode across the fan just in case of spikes when it is turned off. 

It works!