Remove you coolant cap on your coolant overflow and remove the gasket seal from the cap. Save to gasket to reuse later. Replace the cap and ductape the cap with a strip of tape onto the reservoir. This will slow down the coolant loss until you can replace the haedgasket. Your rough start- up is from the headgasket leaking into one of the cylinder and shorting out the spark plug. Relieve the pressure of the coolant before you blow a coolant hose or your coolant reservoir. I had to do this to my Saab 900 until I replaced the headgasket.