Ever since upgrading to Catalina, I have had NOTHING BUT PROBLEMS! It has wreaked havoc on every aspect of my computer. I have even seriously think having Apple help me navigate backward to Mojave. Let Apple fix Catalina before I return to it.

PC security system knowledge is irrelevant to Macs.

You're welcome!

I'm assuming you meant to respond to the OP? Or someone else? ;-)

Examine the “Memory Pressure” graph to determine memory demands—not CPU Load.

That screenshot of CPU Load indicates perfectly normal operation.

👍

It appears all the junk remnants are gone. Good job!

Your Mac has its own X-Protect system built-in. That, and a little common sense, is all you need.

The title of that article is pure click-bait. The only virus mentioned in the article is the Word Macro virus, which doesn't even affect Macs. Most of what is mentioned is stuff that has either been dealt with or that can be avoided with good security practices.

Although MacWorld claims that it's editorial independence is not compromised by the fact that they get a commission from people buying software they recommend, I'm not sure I trust that.

See this article:

Effective defenses against malware and ot… - Apple Community

Third time's a charm. I don't see any of the usual suspects in the report. However, do go to the Clean Up section and remove the orphaned files that's listed there.

Also Malwarebytes is excellent protection from adware and malware it doesn't need to be loaded and running in the background. That only takes up precious CPU cycles and you can't afford to waste any. Only run apps when you need them.

This is because you have the slowest Mac that Apple offers, only 8 GB of RAM and the slowest, 5400 rpm, hard drive. Therefore you'll have to watch what's opened at any one time, i.e. only what's absolutely necessary.

I wholeheartedly agree with idrisSeabright's assessments and recommendation of that user tip.

As long as "McAfee" and "Webroot" remain installed your Mac will never work properly. Uninstall them according to their respective instructions.

"Webroot" may prove difficult to eradicate; a characteristic of similarly categorized junk.

If you have difficulty deleting the Webroot files try this:

1 - boot into Safe Mode (Use Safe Mode to isolate issues with your Mac and Playing Safe: what does Safe Mode do?). 

NOTE: Safe Mode boot can take up to 10 minutes as it's doing some system cache cleaning, volume verifying and directory repairing. 

Booting into Safe Mode prevents any 3rd party software from running making it possible to delete them.

2 - download and run Find Any File to search for any files with Webroot in the file name.  For example do the following search: 

1 - Name contains webfoot

Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.

FAF can search areas that Spotlight can't like invisible folders, system folders and packages.