The moderator didn't delete your post because I didn't actually even see it until now, since I don't work for Microsoft (none of the Volunteer Moderators here do, we're all just volunteer users of Microsoft products just like you). In fact, no one deleted your post, the forum management just temporarily hid the post while they edited it for abusive language or other forum terms of use or code of conduct violations, that they actually could have deleted the posts for, but instead are trying to give you a chance to redeem yourself, so take the offer or don't but stop the abusive language if you truly wish to receive help.
Yes, the Microsoft Authenticator app can be confusing and difficult for some users, though it's worked very dependably for me for several years and that included when I replaced my phone a couple years ago, which is when it's most likely to break for some who don't understand they must ensure there's a working backup of the Authenticator's passwords, TOTP (Time-based One Time Password key codes and other data stored in the app to be restored to the new phone for any existing Microsoft or 3rd-party accounts to continue to work.
Restore account credentials from Microsoft Authenticator - Microsoft Support
You don't need to have two copies of the Authenticator app operating, though that's possible by using the backup to restore to a second phone, but not really useful long term since the TOTP codes including primary Microsoft account code aren't automatically kept synced if they change for some reason, like the username and password portions of the data are. So, keeping 2 phones working would be more trouble than it's worth, though using this method to backup form an old phone and restore to a new one to ensure it's working properly before getting rid of the old one is a good idea.
From your description, it sounds like you accepted the option to use your Gmail.com Google account name as the name of your Microsoft account, which I purposefully avoided for several reasons, including the fact that it's confusing as you've discovered, since to keep the passwords synced between the accounts to make them easy to use, you must change both the Google and Microsoft account passwords together as well.
Instead, I chose to keep my Google Android phone's Gmail account entirely separate (i.e. the usernames are different, username1 at Gmail, username2 at Outlook.com) and use that as one of my alternate Microsoft account verification methods (and vice versa) if ether I forget my Microsoft password or some other verification method were to fail.
I suggest that you try either chatting with Microsoft support directly per the following or use the Microsoft Q&A Forums to request help, since I though I've used the app for years, I've had no direct experience with the types of problems you seem to be having, so I'd personally be guessing what's truly wrong in your specific case.
Microsoft Authenticator - Microsoft Q&A
Rob