Engine Overheating

I have this car since October of 2015 and it has had an over heating issue recently. I could not afford to fix it for a little while, but I found that putting in radiator helped for a couple days or so. I just had the thermostat replaced and it still started heating up within five minutes of driving. I replaced the water pump last night and now I can barley make it down the street without the engine heating up. My check engine light is on and when my step dad checked the codes it said there was a misfire and engine over heating. I do not really know much about cars and I have no idea what else could be causing my engine to over heat. What can I do to fix this problem?