If the aim is to use the original account name, and you can establish a working admin account, you can set that second account up and rename it. ?I had some uninterpretable problems with my account on a 2011 iMac. ?I created a second account called Admin, copied over everything to it, renamed it, and then deleted the old account. ?
You¡¯d have to look up the process for renaming an account. ?There is more than one step and you have to do the steps in the wrong order, flying monkeys will destroy your Mini. ?I don¡¯t recall where I saw the steps but I assume it can be found with your favourite search engine. ??