1992 Ford Bronco overheating/head gasket

I just bought this bronco recently and have had a few minor and now major problems. It was sitting for approx 7 months so when I bought it I replace battery, and changed oil, and topped off coolant. The problem I have been having started a few weeks back and has now devolved, I believe a blown head gasket. So it starts up and runs fine but every few days it seems to hick up, and will die. Just before it dies the ampeage meter goes beserk both dropping way low and then going way high. After it dies and I try to restart it, it cranks and turns over but wont actaully start running. Also at times after stop lights/signs, it bogs out unless you floor the accelarator. Sometimes while driving the amp meter drops and drops the second you let off the gas.

The other symptoms are cooling stuff. I had noticed the car was running hotter then usual, and burning through coolant. I noticed a good size leak in the heater core but not enough to warrant how much coolant it burned through. When I drove home from work it got into the red in temp guage. I turned it off and let it cool for a bit (coolant tank 100% empty) but I had to drive it a few more miles to my house. So I by passed the heater core in the engine bay and then drained/flushed the radiator. After flushing it, I noticed in the coolant overflow tank sticky white sludge that looked very much like water and oil mixed (i have had gasket problems on other cars) and it also showed up on the radiator cap. I checked oil dip stick and oil looked fine. After refilling with antifreeze and starting it up, the car has run cooler but still gets hot at stops and still has other problems. I am pretty sure I blew the head gaskets due to water and oil in coolant recovery and now the oil pressure guage is way low. I am worried about taking the time and money to replace the head gasket with out figuring out the problems first. Any ideas on causes of overheating and bogging down and such?