Whatever happened with your upgrade, you will not be able to access FaceTime or iMessage now that you have changed your Apple ID password. Have you already shut down both apps and signed out of each app, then signed back in again using your Apple ID (email address) and new password?
I've just checked my automatic updates from the App store on my iPad and see that there was an update to iMessenger just 2 days ago. I couldn't see a recent update to FaceTime though. Have you tried opening the iMessenger updated app? You will have to sign in with your new password.
If none of this helps, you may have to delete each app (shut your iPad down and open it again to ensure the apps are gone), then download them again from the App Store and open them. Enter your Apple ID and revised password when requested. If this doesn't work, I think you will have to contact Apple.
If you don't know how to carry out some of these actions, you can google them or PM me. Apologies if you tried all this, it's difficult to work out how detailed advice should be.