If you have a NAND backup, then you should be ok. You just need to restore it. Concentrate on finding a reliable way to enter RCM. Get a jig... order one, borrow one, steal one or make one, whichever works. You just need to use it once, in theory. Then you can install AutoRCM. You could also mod your right joycon like I did, but that's probably overkill.No logo at all I only see a black screen nothing else.
I found the prod.keys files in my SD also I made a Nand backup before my switch stop working completely. There is a 27gb Backup folder in my card. The problem is that I found 9.1 keys but something is wrong and I get an error
You picked fat32. Your switch can’t read your exfat memory card.
Format your card (or a different one) to fat 32 so your switch can read it and then place the necessary boot files.
It’s not rocket surgery.