Modified password without my intervention denying me access to Gmail....I was driving at the time !!

I have had a password modified within my 1Password that is for an email account, and I have subsequently also lost access to that account, its my primary email. I have no clue how this could happen, and can only draw a conclusion I have somehow been hacked. Google ironically will text me a G code as the initial step in recovery, but the second step is an email code, the 2 addresses offered, one is the locked account I can't access and the other is a defunct email with an ISP I no longer have a relationship with. Why Google would send an email code to an account not yet recovered makes no sense to me, how could they be so dumb. So, back to 1Password, I now have distrust for it, and yet it is now and embedded part of my life basically, and I need it. How could this happen, a password be modified when I was away from my machine, but no one would have had access to it. I need to turn on 2 step authentication, as I am hoping it may help in the future, a feature I didn't know existed. Any help much appreciated. Thanks.

1Password Version: Not Provided
Extension Version: Not Provided
OS Version: Not Provided
Sync Type: Not Provided