You can easily replace the Display Module yourself, but you have no guarantee that only your current display is faulty.
When your phone takes a dive, you should allow it at least 2-3 days to dry altogether. It often happens that people don’t give it enough time to dry, restart it again soon and find it “still works” – only to find it will still start to malfunction later because there was still humidity deep inside the phone parts, but not visible to the eye.