[mrhyperpenguin]

The OP checked the "stay signed in" option when logging in to his or her Google account on another computer and all of the accounts that were logged in were listed in one menu. He thought Google had merged the accounts and ended up deleting his account.

The solution is simple, just click the sign out button and Google signs out all accounts that are configured to "stay signed in." Alternatively, he could have cleared his cookies or waited for them to expire.

Some people have been saying this is because of bad UX on Google's part. Google is kind of in a catch-22 situation here. They want to upgrade how multiple users check their Gmail on one browser but no one wants to learn how use their new system (I got frustrated when they introduced their new UI to compose emails and had to show a tutorial on how to use it.)

[SeanDav]

Here is a thought - why don't they use the email address and password to distinguish between users....

[jonknee]

They do... The problem is a possibly confusing UI for multiple sign-ins (distinct email addresses and passwords). Most sites don't have this as a feature so there's not a standard UI for it [yet].