Google drive backup not working

tl;dr app fails to restore a Google drive backup and also won't work on general. Pls send help

I have two major problems.

First is that a few days ago my WhatsApp had started misbehaving, the app didn't open whenever I tried to use it. If I tried again and again many times, it would work for some time but eventually go back to the same problem. Restarting the phone and deleting cache didn't help at all. WhatsApp Web kept working without problems.

I figured I could just reinstall the app, so one of the times it worked for me I manually started a backup, and it managed to complete before the app returned to not working. I could clearly see it said the backup was complete and had the right details for it. I uninstalled and reinstalled, and while registering it did find the backup in the drive, but after some time restoring it, it gave a message that it couldn't restore the backup and asked if I wanted to use an "older" backup, tho when I let jt try doing that it seemed to find a local backup that was created just a few minutes before. After that it got stuck on a "restoring..." screen, at 100%, and wouldn't change for literally hours, usually eventually giving up and suggesting, again, to use an older backup.

I have tried again and again multiple time, and eventually I gave up, and skipped the restore, losing over 8 years of chat history, and I'm honestly devastated by it. I have set it to backup to a different Google account so the original backup cutlrrently exists.

To add insult to injury, the original issue had returned, so my loss was in vain.

I have searched the Internet for advice but nothing worked for me so far. If anyone here might have any idea about how I could restore my chats (right now I don't mind losing stuff from after the loss), or how to make the app work at all for me, I would be eternally grateful.