Stuck in a doom loop where my email address is linked to a microsoft account, but the account itself does not exist

I created a microsoft account using a gmail address -- not the one I am using now to post this question!--I use that account for Family Safety and for Minecraft.

I was logged out and when trying to log in I get the message:

Det gick inte att hitta ett konto med det användarnamnet. Försök med ett annat, eller skaffa ett nytt Microsoft-konto.

So not recognizing the email address as a microsoft account. When I go ahead and try to create a new account using that same gmail address, I get an error saying that the email address is already taken. How can I get out of that doom loop?

Moreover, this is the account that is linked to Family Safety, so I cannot edit my son's screen time anymore. I tried linking it to this address, but it is not allowing me.

I tried to call support but ended up even more frustrated as it is impossible to get any help.