Cant get into Account

Ive tried logging since Ive had an online account before using the app. But it wont let me in. I as well tried resetting my password but it keeps saying that my email isnt an valid email account. With that being said I tried creating an account, but then it says this email is already being used. Itd be nice if someone could help me as I dont think the app is running properly for that. So help!?

Doug O Maley about BookBub, v1.0.2