I don’t know how to do a time machine back up and from what you say it runs the risk of adding in bad programs.In the activity monitor you should be able to see which processes are using the CPU, so there's no need to guess what is causing your problems.
If you use Time Machine it will back up everything that isn't a system file, so if you do a complete restore from a backup then you would run the risk of experiencing the same issues if is indeed a specific piece of softare that's causing issue. On the other hand doing a clean install and restoring from Time Machine may still help as it ensures that you are starting over with a clean slate. My method is usually to do a clean install, restore documents and other files that I need, and only install software that I need when that need arises. It's easy to fill a computer up with old software remnants if you go years without doing a fresh reinstallation.
All I want is to have my Adobe programs when I do an install. Is this possible.
I need to do an install today. I’ve lost days now with no real working computer. I’m in safe mode now.
Ill try Catalina.
What is the best way to do this?