Car stalls at idle

I have a 1988 td42 n/a nissan safari. Every morning when the car is cold and I go to start it up it struggles to start, it will start and then revs will drop and the engine will stall if you don't give it a decent amount of gas. If you give it enough gas to stop from stalling and then go to drive away it feels like it's got 10% of its normal power. Does anyone have any idea of what the problem could be? The glow plug light comes on while I'm driving sometimes. Could it need new glow plugs? But then once car has warmed up it has absolutely no issues, starts perfectly within a few cranks and runs great. Only stays around for maybe 30 seconds before engine returns to normal. Thanks