24 Mac Air unbelievably slow, spinning beachball.

I've restarted several times, shut down all windows and open documents, deleted all unused applications, purged unneeded files. I have about ½ of my memory and ¼ of HD space available.

Running Sequoia 15.5. Ran Clean my Mac several times. Backing up everything now. Any suggestions before reinstalling OS? I don't remember what I had last installed before this happened, but it started with incredibly slow typing in the past few days. Sometimes it seems the track pad doesn't work on clickable things. Other than that, the only problem was that when I just put it to sleep, it would shut down and I would have to restart. And every time I restarted, my Contacts would disappear and must be found on iCloud, and all open documents came back to the dock with the same name. Help!