Hi @Shelmoh,
Are you sure that you "have changed" your email associated to the Dropbox account or, may be, you have signed up new Dropbox account with the new email? Did you change the email assigned to your account here with "Edit", next to your old email? If not, you have signed up new account and that's why it's empty. In such a case you can still access your old (non empty) account using the old email. If you want, the email could be updated after deleting the new account; the new email must not be assigned to Dropbox account.
Hope this gives idea.