18.04 – Screen freezes for about a second every 10-30 seconds

My display keeps freezing for about 1-3 seconds every 10-30 seconds. I notice in the system monitor that gnome-shell tends to accumulate ram. When it gets to using more than a couple gigs I restart it with Alt-f2 -> r which resets it memory usage to <200mb. This seems to help for a little while but the problem doesn’t go away completely.

I’m thinking it’s a display issue because any time there is an animation or video playing, after each freeze it jumps ahead to where it should be had it played continuously. When the freeze happens while I’m typing, I continue typing like normal and when it finishes the freeze everything typed during the blackout suddenly appears like it should, no missing characters.

This problem started after using Shotcut to edit a video. I did something that locked it up completely. The hard drive light went 100% and stayed that way. I figured I maxed out my ram (16gb) and it was swapping so I gave it a while to work through what it was doing. After about 10 minutes it never stopped so I hard reset. Apparently that did not go down gracefully as I’ve had this glitch ever since. I’ve tried reinstalling gnome-shell but that didn’t help.

I’m not sure how to troubleshoot what is going on. Could someone help please?