I guess I would ask what is causing your inability to type? Is it too wide for one handed typing? Are all the possible keyboards messing up words for you? If the Samsung keyboard, Gboard, and SwiftKey are all failing you, I'm really curious why. There are one handed modes if that's the issue. You can enlarge the keys if you aren't hitting the right letters.
When I press the keys the one next to it is often what shows up. I've noticed some lag so I have to type slower than previous phones which sometimes helps. I can give Swiftkey a shot.