Maybe you unplugged the device before unmounting it leaving the filesystem in an odd state? Next time it fails to auto mount check /var/log/syslog for recent error clues.

When I worked for a telco in the 80s they had a nightly script for two backups over three tapes. The script asked the operators first for tape 1 then tape 2. Started the second backup which asked for tape 1 again. This overwrote the first backup. Tape 3 was never used. I found that problem before they ever needed a restore.

In Australia you talk to your primary doc to get a referral to a psychiatrist. Diagnosis as an adult they will both be suspicious that you are just after amphetamines. My brother succeeded with a diagnosis as adult. Best of luck.