Good-news-bad-news first. If there are disk errors, the good news is that you caught it before the disk became BROKEN. [non-technical term] Bad news is you need new drive(s). Most of us would recommend a minimum of at least two drives, but that is another subject.
Triage: Get multiple good backups, as well as a copy of the Imported Items directory [as a minimum] onto an external disk. There are probably other files you need, so a full backup would be preferable.
Next up, buy the drives you need, and when they are in-hand, pull the old drives out (labeling them), and install the new drives. Then try the BMR - worse case the BMR goes sideways, and you go back to your other drives.
That way you have a path back, even if it is imperfect and won't last for ever.
Suggestion: also buy a cabled webcam that you can attach to another machine (laptop) so that you can get remote eyes-on.
You can reach PM me if you need someone standing by during the 'surgery'.
