Last weekend I noticed my Mac was running slow. I did everything suggested. I upgraded to the latest version of Sierra, bought and ran (multiple times) Clean My Mac. Now it's so slow that I cannot do anything. Before the upgrade I was able to look at Memory and quit processes. Now I can't even do that. If I click on something,nothing happens. It's MUCH slower than it was. I feel as if it's worth nothing now. I have not been able to use it for days. I'm at a loss.