Powershell Stopped Working Computer Extremely Slow

I know everyone is busy these days but if anyone can help me out I would really appreciate it.  For the last week my computer has been running extremely slow.  Upon running a virus scan it indicates that all issues and threats have been fixed, which help for a little while.  Then I keep getting a pop up that my powershell has stopped working.  I have high CPU usage popping up all the time and my computer has shut down on it's own a few times now as well.  I am not too savvy but I can follow instructions if anyone has patience to help me out!