Need Adobe ID to open book in Nook and change email address in Adobe Digital Editions 4.5

I have a Nook GlowLight Plus and the Adobe Digital Editions 4.5 on my computer to sideload the books I check out of the library. After I have sideloaded the book I can not open it. It requires log-in. I have tried every login I can think of and am stuck. The Adobe Digital Editions 4.5 has an old email address which is deactivated and I don't remember the password anyway. Nothing can be retrieved from the old email address. When I opened my Nook GlowLight Plus I see My account is my husbands email address.When I look in the Adobe DRM Settings I see my old inactive email address (same as in the computer Adobe Digital Editions 4.5), my husbands email address and my email address. I use my account at the public library to get the books on the Adobe Digital Editions 4.5. I may have several issues here. I looked at your forum and tried to follow the steps change the email address in the Adobe Digital Editions 4.5 but at a certain point I couldn't do what the next step was and gave up. I need help. Thank you. Nell