I have an i5-2400 since I had no intentions of overclocking my computer and I've had it for almost 2 years now. I clean it regularly but a month ago I took my CPU fan off and cleaned it out completely but didn't have any new thermal paste so I just put it back on. It worked and ran fine up until yesterday. Now when I'm idle my motherboard says the temp is at around 40-60 and I looked at additional software to confirm that. Now when I play a video game it goes from 40-60 to 95+ in like 30 seconds and I get like 2 fps and stays there till I quit the game. What do I need to do to stop this? Buy a CPU cooler?