Does that work?(I have never used pause before)
If so,
Make a global variable called "Pause" initial value =0
When clicked on pause button,make it 1
If 1 AND clicked on pause button,make it 0
If "Pause"=1 ,Disable group
If "Pause"=0,Enable group
Hmm nothing happened, also if i only use P pressed = Timescale 0. The Game just run normaly.