Coolant issues in a 95 3.4L DOHC

GAH this car is killing me!!!

a couple weeks ago I dumped my coolant all over a mall parking lot, that turned out to be the hose coming (or going, not sure) from the heater core. With that fixed the car ran nice and smooth, till today....

I drove to work and when I got there the car was over heating, not quite in the red. I popped the hood and the reservoir was full and bubbling. At this point I am convinsed that it is my thermostat stuck shut....
I get out of work and top off the rad, didn't take much. Then I fire it up, it sounds like its running on 5 cylinders... It was running for about 5 minutes before I shut it off. Once it was off a passer by pointed out that I had coolant on the ground, the source was my exhaust, where the pipe ENTERS the muffler on the passenger side. After that I tried to start it again, nothing, the starter engages but nothing happens. Everything else electrical checks out, stereo headlights all that junk work, so I think battery is ruled out.
There is no coolant in my oil and no evidence that any has been puked up through the intake, the filter is bone dry. When I had the car running there was no big white cloud, so where all that coolant came from is anyones guess.

Someone please help, offer up any suggestions.

My major question...is my engine toast???

Thanx

Jamie

Unfortunately it sounds like you may have blown a head gasket. Remove the plugs and see if you see any water in the cylinders or on the plugs. The overheating probably caused the problem and I would guess that there was air in the system that caused the coolant to boil in the reservoir and caused the overheating, not the thermostat.