re: Press - some days it will be that way. Keep with the 5s until there's actual failures. Then there are programming changes to keep moving that weight upward (changing to 3's isn't the way), but don't worry about those yet. You still have a way to go.
One thing that might be contributing is that you are letting the bar roll back into the middle of your palm, which puts way too much pressure on your wrist, which will become problematic. You want it to be directly over and inline with your forearm as you press (both overhead and bench).
Here's a good video on the details by Phil Meggers.