1988 Honda Civic 4 door Wagon around 180000 miles

My car has been acting weirder and weirder. I am not even sure how to describe everything as it doesn't always happen.

It doesn't like to start. It hates starting unless it is parked on a slight up hill. It starts to crank but the engine won't fire or whatever. I have wondered if the plugs were bad.

Also, right after starting, when I go in reverse, esp. Up a slight hill it doesn't like it and also blows white smoke. Yesterday it was VERY bad. After that the engine light went on after pulling a long hill, going 25 lbs per hour. The engine lost power as well.

I have had to replace the coolant more and more too as one day it tried to overheat. Since then I check it all the time.

The engine also sounds rough and takes awhile, and some gas to get it ideling properly.

I know it might be the head gasket, but I wonder about what else migth be wrong. Plugs, timing, etc.

Any HELP would be appreciated since we lost our mechanic and I want some idea before trying a new one out !