PC Hibernating/Freezing

I made all the upgrades at the same time. Within the past 2-3 days I have had issues with my PC going into hibernation/freezing (either losing monitor input and audio at once while the PC itself is still powered on and running or the monitors freeze along with audio). Afterwards, I will completely power down the PC, let it sit for a few minutes and then reboot. This has happened in some variations, either during a few games of Rocket League, Hell Let Loose, etc. Or after running the applications for 10-15 minutes and going to close them.

My resting temperature on my CPU has been between 43c - 51c.

While running these games the CPU temp is typically between 68c - 75c.

I have messed with underclocking the CPU to see if the temps would drop and give me a solution but that has not helped. I am worried my CPU might be running at too high of temps, especially in the 30L case (known to be small with lack of good airflow).