I still at times have that exact problem that you've touched on.
One way I went about attempting to overcome this was by focussing more on my approach and release rather than wether I was going to strike or not.
My key is bend the knees, through with the shot nice and slow and make sure the hand is behind the ball and push through it when I'm sliding, rather than go around it.
I used to (and still do it occasionally) release the ball in the fudgey, suitcase position - hence why I have left more 5-7-10's than anyone in this country probaly.
But I'm slowly getting better at it......I have a whole 5 revs now.
Sometimes my mind still wanders when I'm struggling though......I still think of which wall to punch or which bowling ball is going to go Weeeeeeeee out into the carpark, next.
Or how many rude words I can deliver in one sentence about how good tonight's lanes are.
I have a rather volatile temper sometimes and I find it rather hard to keep it in.
These are things that are rediculous and I'm making a big effort to try and snap out of that......I'd be quite grateful if any other very hot-tempered bowlers out there might be able to offer me some advice on how to keep cool...I need it.
Have a good day Y'all