I don’t remember the email address that was used to establish my account.

 Thanks for posting to this public discussion forum, ​@LAURA HOCHFELD.

I appreciate your long-term use of our software and I apologize for any problems you have encountered accessing your previous purchase.

What version of Photoshop are you trying to download and install? I see that you did contact us directly and mentioned a serial number, but there are not many other details available.

Please see 

 for information on how to download and install older versions of Photoshop and Photoshop Elements. You will need to be logged in under the correct account to access the files, and I don’t see any software titles registered under the account you used to start this public discussion thread.

Please see https://helpx.adobe.com/account/individual/sign-in-and-security/security-and-recovery/reset-adobe-password.html for details on how to request a password reset if you do recall the email address that was used to register the software.

use https://helpx.adobe.com/manage-account/kb/unknown-charge-on-bill.html?linkId=100000379229962 to find your account.

This is a public forum, not Adobe support... other users can't help
This is the new CORRECT way to contact support
https://helpx.adobe.com/contact.html?rghtup=autoOpen

- and enter AGENT in the box asking How can we help you?