How to recover lost books on iPad?

I make a huge mistake and hit a wrong button losing my original book app and lost all books. I could read a book but had no ability to look at other books or my library or add a book I would like to read in the future . In frustration I deleted the app. Reloaded the book app from the store thinking if I used by user name and password that I would recover my over 17 years history of books read. No luck. Is there anything I can do to recover my old app as it was. I would greatly appreciate any help you can do. Thank you. Barbara

[Edited by Moderator]