You have to press the heatsink posts into place until you hear a click. Make sure the top disks are correctly oriented.
I thought I had done that, but apparently I didn't push down hard enough. One of the posts wasn't clicked it. Now it seems to be running fine; Windows installed, my CPU temp is chillin around 35C, and no blue screens yet. Thank you so much for a simple fix. I feel kinda dumb now though haha.