1998 Dodge Intrepid Do I need a new engine?

I have the 3.2 liter not the crappy 2.7 engine Dodge Intrepid. About a week ago it suddenly overheated (really overheated- blew the coolant overflow tank cap off). I let it cool down and drove to a auto parts store after putting about 12 bottles of water in it. It overheated again as I entered their lot. They sold me 3 gallons of 50/50 coolant. Drove it to the shop at work. Our mechanic flushed the system, replaced the thermostat only to find the electronic fans where not working. Replaced both fans but the would not turn on so we sent it to the dealer.

The replaced a sensor to get the fans going again but the tech told me my engine is most likely shot (his opinion) because it got so hot. He told me it was smoking bad and running hard and that there was some (not a lot but some) oil in the coolant. He stated the most likely culprit was a bad head gasket or the head itself. After getting another opinion I choose to follow the second opinion and drive the car to see what happens.

When I drove it (no smoke and not running hard) it did not immediately overheat but it did slowly (then more faster) start blowing steam from the thermostat (from what appears to be some kind of valve). That valve was loose so I tightened it. Then the worst happened I took about a 10 minute trip on the interstate and it overheated. When I opened the hood it was bellowing steam from the same spot and when it had stopped I noticed my overflow tank was completely empty! I managed to get the car to take about 2 gallons of premix 50/50 coolant water mix but it keeps steaming from there and boiling out all my fluid from the cooling system. Do I need a new engine? Or could this be a less complex issue such as a cooling system problem or a head gasket (pain to change but cheaper than an engine). Please help. I cannot really afford a new engine ($1500) right now but if it has to be done it has to be done.