95 Ford Contour. 116,000 miles

My wife had this car in the shop when we first met. We got it out of the shop after having several things replaced. The car ran fine for about 6-8 months before it started to have an overheating problem. One day while I was driving it the car suddenly made a hissing sound and died. I got the car restarted and pulled it off the side of the road. I noticed that there was smoke coming from under the hood and I checked to see where. The smoke was actually coming from the coolant reservoir tank. I wasn't sure of the problem so I had it towed to the shop where he said it was the head gasket and that he would relace it for $1700, I thougt this was high and didn't really have that kind of money at the time so I had it towed to the house where it sat for about a year. I recently decided to look into it further. I got it running but when I took my foot off the gas the car would die. It will not idle at all. I notice a blueish white smoke coming out of the exaust, there was also what look like oil spitting out the end of the exaust. I figured that this was the sediment from where it had sat for so long. I would notice that after running for a few min. The smoke would start to dissipate. I kept trying the car for about1 1/2 hours berore the same hissing sound started at the coolant reservoir. I also notice that the coolant level when hot would go down not up. I had thought at first that it was a fuel pump problem, but since the coolant levels seem to be changing so much I was wondering if it is the head gasket. If not what other suggestions would you have. Thnks for you time I am really stumped. I am not a mechanic but I do have a little car knowledge.