Which version of Acrobat (including minor) are you using, on which platform (Win/Mac), which OS (and its version)? By saying that "they don't support acrobat x" do you mean that you are using Acrobat X?
Which account where you reset password are you talking about? Is it Adobe Document Cloud account? How it relates to Acrobat X? Are you using certificate-based digital signatures? If so, then go to Acrobat Preferences and check which Digital IDs you have installed. This list is where Acrobat looks for the Digital IDs to sign in the 'Sign" dialog's drop-down list. You may have done something while changing password that changed your Digital IDs even if you did not do that intentionally.
I'm using Acrobat X version 10.1.16 on a Mac (OS X v10.9.5). I'm using the software not the document cloud account. Not sure if it's cert-based, before I would just choose Sign Document under Sign & Certify. I'm looking in preferences but don't see the Digital ID list.
If you do not see your Digital ID in the Digital ID list then Acrobat does not see it either and cannot show in the "Sign" dialog. I do not know what has happened with your Digital ID. Could you accidentally move it to a different location or deleted it?
How did you procure your Digital ID? Have you gotten it from a Certificate Authority (CA) or created a self-signed Digital ID in Acrobat. In either case this is a password-protected .p12 or .pfx file that resides somewhere on your machine. If you received it from a CA you may be able to get another copy from them. If this is a self-signed Digital ID the easiest solution is to create a new one with the same content as the old one. You can search your Mac for *.p12 and *.pfx files and it just gor moved somewhere you'll find it and re-add to Acrobat's Digital IDs list.