Problem with secondary account

I've an issue regarding the deletion process, apparently I've got 2 account, my main account with all the content I bought, my characters, my homebrew, etc... and a second account (probably the first one I made) that was apparently created from twitch, with nothing on it.
Both account have the same  E-mail address listed. (because the secondary was created from  a twitch account with the same E-mail)
I'd like to delete the secondary account but since they both use the same E-mail address I'm scared that they would delete the main account instead, or both.

Any idea how to deal with the issue ?