Expired email account

I have a seemingly serious problem with my Zoom account, and now am looking for a solution.

My Zoom account was and still is connected to my old email address, which is no longer existing, neither possible to retrieve. (I thought I have changed my email attached to the current email address of mine, but apparently failed to change it successfully.)

It was a Gmail account of one educational institution (not personal email, therefore), and I chose to set in my Zoom account with the option of "Login with Google Account." So I neither have a simple password which I can try to enter to log in.

Now, what should I do to access to my Zoom account or Zoom profile page without having an access to the email account? My Zoom app locked me out, I could not enter my profile page because I can't get the host key via account.

I tried to reach the Admin. but failed as the call on the phone also required me to have some digit numbers, which I would not have an access without having a functional email address.

Thank you, in advance.

(This question is obviously posed via my different Zoom account page which I had to make for only to ask this question.)