|Install Process Explorer from Microsoft to get a better picture of your processes, what is running, etc.|
Use msconfig and go to start up tab and uncheck all except Microsoft and antivirus, OK, and restart computer (you can always add back a few later). You should see much less running and less memory used.
Scan with Malwarebytes if you suspect an infection that might have got past your antivirus program (everything cannot be picked up evertime, this will be a double check).
Depending on the programs you run, you may consider adding more memory.
You have to be a little bit crazy to keep you from going insane.