Basically, you just need a password manager.

I use https://en.wikipedia.org/wiki/KeePass

You can store the other details in the notes - e.g. which card / account is used for payments, what are the password reset questions & answers, which address is set for delivery.

Then, when you change credit cards / addresses / emails, etc., it's easy enough to find all the accounts you used the old one for and need to update.