Switching iTunes to a new email

I have an iTunes account. In 2017, I lost the email account that it was under it. I can still listen to my 4,000 songs, however I want the library switched to my new Apple ID. I called support and they hung up when I took too long to answer a question, I went for a computer chat and it left me hanging with a message saying it will be 2 minutes for way over 2 minutes and now my local Apple Store isn't providing any help. Can you?

PS I know the email for the old account, but not the password. I've been trying to get this fixed, off and on for 3+ years.