Yeah its tough. You want to make it so you are doing it every time you play no matter what. You need to be split stepping and basically you should fix your footwork. I spent a lot of time on that and everything else clicked into place. People are going to focus on what your arm is doing..etc, but if you start with the feet, you will see a lot of improvements.
Right now it looks like the game is too fast for you and you are trying to catch up. The reason is because your footwork is not there and you are not anticipating the next ball. Even if you are, you are not able to get prepared for it in time.
I love this guy's website for footwork. It is a lot of stuff, but if you just start with the basics and only focus on that, you will see a difference.