Dell 5520 shows black screen after login following latest Windows 10 update

Everything was working fine before I installed the latest Windows 10 automatic update. Now I can boot to the login screen and things looks good, but after I login I’m stuck on a black screen. I can see a mouse cursor and if I hit curl+alt+del I immediately get the customary blue screen with options to Lock, Switch User, Sign Out, etc. But if I choose the Task Manager option I go back to the black screen and get a spinning cursor for a few seconds, then it goes back to being a regular cursor and nothing happens. So basically I’m stuck on this black screen. It’s not COMPLETELY black, since I can see the cursor, I just can’t go anywhere. I can also, sort of, boot into safe mode. After login I’m on a black screen that says “safe mode” in the corner and I see black and white Windows start button in the bottom left. Unfortunately, moving the cursor anywhere to the edge of the screen (eg over the Windows start button) shows a spinning cursor and if I click, it says “The application is not responding. The program may respond again if you wait. Do you want to end the process?” but of course neither option has any effect, it’s always a spinning cursor. Any ideas?