I just got down on my table and noticed when I shoot harder my wrist will twist Inside. ( my thumb will go from pointing down to pointing at the side of my body. How do I fix this?
OK, good observation. Now your problem can be fixed. I hope you take my advice because I can help you.
Set up a straight-in shot and take your thumb and index finger of your grip hand completely off the cue. Let them hang down straight towards the ground without touching the cue. Then shoot the shot. Make sure they are still pointing down after you've shot the shot.
This is just an exercise, so don't panic. Keep shooting that way until you can successfully pocket the ball several times in a row.
Then you can slowly start to place both fingers back on the cue VERY LIGHTLY.
If you start to twist again, take them off and do the exercise again.
You need to learn how it feels to shoot straight and your first two fingers are preventing you from doing that.
Trust me. I know what I'm talking about.