I tried logging into Pokemon Go after not using my account for a few months, but I found myself unable to login - apparently my email address does not exist! I even have a screenshot of my registration email that was received on that email address, so how could this be? Please help me log into my Pokemon Go account.
It turns out that when I changed my email on Ingress Prime, my Pokemon Go login email was changed at the same time. The two accounts' email addresses are linked and you cannot separate one from the other if both were tied to your Google account.