Still no response to this, but fine, there’s been a change anyway.

Now, Avast is no longer messing with my disk or memory, and also isn’t going in cycles. Instead it’s constantly using 100% of the CPU.

If nobody has any insight into this problem, can somebody recommend another reputable free antivirus program? If I wanted to keep using something that caused me as much trouble as an actual virus I wouldn’t have uninstalled McAfee.