Yes you can backup. Using the smart switch app, you can either backup to the cloud or backup to your pc.
As for an emergency software recovery. Install smart switch on your pc. Shut your phone down, connect it to the pc via USB. I believe you hold volume up and down till the screen turns teal, if it's been over 15 seconds something isn't right. If it works, follow what the phone says (you are not installing a custom os). When it says you are in download mode, open smart switch on your pc, 3 dots top right, emergency software recovery. It should guide you to wipe the phone and reinstall the latest android onto it.
Then restore your backup.
Emergency software recovery is the "well everything else failed, this is the nuclear option that should work". It's designed for if an update fails or if a phone is bricked, download mode should always allow it to be brought back to life
