The title says it all  

I’ve heard of people merging accounts but only in extremely rare cases. Such as when a email provider discontinued service suddenly

So yes I’m sure it’s possible and if you had a valid reason for needing help, I’m sure you could work out the details with an admin  

Identified accounts can't be merged or have items transferred between them.

However, if you need an email change, email [email protected]. If you can, send the request from the email that the account is currently using. If you can't do that for whatever reason, provide as much information about the account as possible to prove ownership and explain the situation.