Help! I cannot access my Microsoft 365 business account

PSA: Sign into all your Microsoft accounts now and enable all authentication methods, app, text, phone, and alternate email.  Don't let this happen to you:

I am the only administrator and I cannot sign into office.com.

When I sign in, it asks me to enter a number in my Microsoft Authenticator but I do not have Microsoft Authenticator.  When I select "sign in another way" it asks me again to use my Authenticator.

I contacted Microsoft and they told me I could restore access at aka.ms/prosupport.  However, I cannot use the website because it requires me to sign in.

I opened a ticket using another tenant and they told me to call 800-642-7676.  I have been on hold for 3.5 hours now and I do not expect they will take my call or provide any useful support.  If they do, I will post back to share what happened.

Does anyone here know another way to restore access to 365 that doesn't require access to 365?

Thank you in advance!

Update: After 5.25 hours on hold, a voice told me, "All support agents are busy.  Please try your call at another time.  Goodbye." and hung up.  The phone number was a dead end.  Later, I called other Microsoft numbers and they all led to the same queue, voice prompts, and hold music.  I waited at least 1-hour on each attempt for someone to help me and no one did.