Which leads me to another question. Does the passphrase have to be any certain format? Do upper and lower case matter? Could I have used numbers or special characters, or is it letters only?
The mnemonic passphrase can be basically anything, even spaces in between or trailing. Therefore it needs to be documented very carefully.
I forgot, if there's some defined sanitation, like multiple spaces are sanitized to one only. Definitely upper and lower case chars are distinguished, numbers and special characters, all allowed. IIRC, all UTF-8 is allowed.
That went smoother than I expected, to be honest. Congrats to your recovery success. I hope you learned a lesson or two...
A little advise for the future:
if you create a new wallet, document a few things carefully, like
- reason or purpose of this wallet
- date of creation
- which software or hardware was used, with version details
- mnemonic recovery words (flavor used: BIP-39, Electrum, Azeed)
- some hint if mnemonic passphrase is used (mnemonic passphrase needs to be backed up separately)
- derivation path
- if different accounts are used, purpose of those accounts (account level of derivation path)
Pay attention to secure and redundant backups. It's worse to document too little than too much in my opinion. Never try to rely solely on your wet brain memory, it will fail you sooner and surely later.
Never completely destroy recovery details even of wallets you don't use anymore. You can't know if you will ever need those details again for some unexpected reason. It's easier to lower the storage security of such abandoned wallets than face the issue to need the recovery details and don't have them anymore.