Got no Idea whats wrong

1997 Mitsubishi Eclipse, 68,000 miles, 4 cylinder. I was driving it yesterday and heard a pop like noise from the hood area. A few miles down the road the car seemed to hesitate like it was going to stall, the check engine light started to flash and the car seemed to lose power. It didn't stall but the pick up was not what it was usually. The hot/cold needle went from c to the half way point almost instantaneously, never all the way to the hot. I turned on the heat and ran the fan full force. I drove it 2 miles to my house. The needle never left the half way point which it usually goes down whenthe car is in motion. After it was cool I checked the water level in the radiator and it was full. I have no idea what could be wrong and as I am not car experienced I need some advice as to what it could be before I take it to a shop and let them sell me the Brooklyn Bridge. I'm just an old woman who needs help. Thanks.