App Store won’t accept my Apple ID and password even though it is valid

My phone is basically crippled, I can’t use the App Store I can’t use apps that need updating, when I go to the App Store and try to update something, it asks for my ID and password, when I enter them, that box goes away as if it accepted it. But then I click on the update button again, and it just asks for my ID and password again and the same thing happens. When I go into settings and App Store or iTunes, and it asks for my ID and password, I enter them, and the box shakes as if it is invalid. When I keep hitting enter it locks out the account. Go through the security questions, at some point it asked me for the ID and password, I entered them and it accepted it, the account was unlocked, but when I go back to App Store the exact same thing happens. At no point in going to the App Store and entering my ID and password, does it say that it is invalid, the box just goes away as if it accepts them, but it doesn’t. In another thread, someone mentioned that it might be because a particular app is tied to an old password, but how can I enter an old password just for that one particular app, it asks for the password for the Apple account not for an old password for an individual app. And if I change the password, it’s going to be a new password not the old one.Please help Not sure if this is even posting in the right place, there’s no section for App Store, there is one for iTunes but I don’t use iTunes so I don’t even know if this is in the right place thank you