Logging onto deactivated Facebook account

I finally decided to start a new Facebook account after a one year absence (deactivating, not deleting) but decided to keep my old account for messenger. After switching accounts to look at my new messenger account, I was logged out of my old account while also forgetting that account’s password. Even with the login recovery mode and forgot password feature I get messages that read that there’s no phone number, email, or name associated with my old account. I gave up after numerous login attempts locked me out of the old account.

Any way to change a password for my inactive account????? Please help