If you cannot find your papers or you cannot locate your paying subscription, then the first thing to check is that you are logged in to the correct account.
There are 4 ways to log into Bitpaper:
Google SSO - When you use your Gmail credentials to log in to Bitpaper
Facebook SSO - When you use your Facebook account to log in to Bitpaper
Email + password - When you use your email and pick a password to log in to Bitpaper
TutorCruncher - When the Bitpaper is accessed through the online whiteboard link within your TutorCruncher account
On Bitpaper, your paid subscription and papers will be linked to one and only one of these login methods. Make sure you log in the same way every time to avoid creating multiple accounts on Bitpaper.