Try a Windows restore point..?
Try booting in safe mode and follow the AMD guide to completely uninstall GPU drivers & software?
When you say black screen does the entire computer freeze? E.g. CAPS lock won't work, no sound etc. Or is everything still running except for no display?
Long shot.. But try alternate display port ie. DVI instead of HDMI or vs versa.
Windows 10 should bring up a troubleshooting / repair mode if it fails to boot correctly 3 or so times. Might be possible to repair or restore from that?
Also if keyboard is responds you could try
WIN+CTRL+SHIFT+B which reloads / restarts the display. (Did a quick test on mine after a restart and doesn't have to be signed in to activate.
