alright, i figured out it was actually my CPU overheating. i guess i had a misconception of what temp it should be. i think what happened was, when i installed the new CPU cooler, i didnt properly clean the old thermal paste off, and then i applied too much of the new thermal paste.
i've ordered acrtic cleaner and arctic silver paste from newegg to remedy this problem. i've also ordered a new, robust 400W dual +12V PSU (i was going to get one eventually anyway).
thanks all for your help. it is appreciated.