Good idea to backup if you haven’t already.
IMO you would be best served starting from scratch
11.2 to 11.1 is not really an upgrade and FYI, unless you installed 11.2 deliberately with ext3, moving back to 11.1 might not work, because 11.2 default uses ext4 which will not play with 11.1
It’s difficult to say how messed up it is. I know that Linux doesn’t load up.
This is going to sound stupid but this is installed on my “laptop” which has a broken screen, so I use an external monitor. Unfortunately, I can’t really see the error messages because the external monitor only turns on after Linux has properly booted.
I’ve already backed /home. So I’m happy to do another clean installation again with /home left untouched.
The only reason I didn’t try to do this in the first place was because I spent countless hours trying to configure things on my system and was afraid I’d loose all that if I do a clean install.
It comes a bit as an afterthought and I admit that I often have to force myself to do it, but it is very wise when you configure less obvious things, to write them down (maybe on paper, but in a document inside the home directory of the user you normaly use is also a good idea).
Also I do make backups of /etc so I at least can see what I had. I do not advise to bluntly overwrite a configuration file in your new installed /etc with the backup file of the same name, but an intelligent merge is often making life easier.