You should contact customer support through this link:
https://support.spotify.com/contact-spotify-support/
They'll help you migrate your Premium privileges (if you have them), library, playlists, friends, etc. to this new account.
They take, at the most, 24-48 hrs to get back to you.
Don't forget to check your spam folder for responses as they may end up there.
If you get an automated email directing you to the community or help pages, you need to reply directly to that email (even if its from a no-reply address) and one of the customer services agents will get back to you.
Hey there you, Yeah, you! 😁 Welcome - we're glad you joined the Spotify Community! While you here, let's have a fun game…