Not that screwed if youre on an unpatched RCM system, just wait for the CFW to get updated. On the other hand if your system IS patched well...okay guys I accidentally updated to 8.0 ….how screwed am I?
You can extract the saves from your backup before doing the downgrade. Lockpick_RCM even got the 8.0.0 support now so it dumps all you need.You can also downgrade manually without a backup: https://guide.sdsetup.com/usingcfw/manualchoiupgrade but it's a long guide and you *may* loose savedata. Don't attempt this if you don't know what you are doing and read all the warnings.
It's lovely that Nintendo didn't blow a fuse this time around.If you have nand backup of 7.0.1 OFW you can restore it to that nand via hekate restore.
I just helped someone with this issue and we did got it downgraded with nand restore. It was a success!