My Micra loses power when I dip the clutch

I have a 1 litre Micra wave 1994 manual car with 54k miles. When I dip the clutch the engine revs drop, sometimes it cuts out altogether. The heater and head lights also dip when i dip the clutch. It happens quite often now but it happens randomly so i never know when its going to do it. Sometimes it doesn't start straight away after it cuts out, the engine just turns over but doesn't quite start. I have to take the car out of gear at traffic lights and junctions so i can rev, just to stop it stopping. Any suggestions would be appreciated, as i live on an island and the few garages we have just see you coming and charge the earth for half jobs! thank you