Just got back from practicing and was suppose to be with my new ball - Centrifugal Mass, but the thumb didn't feel good and so my driller is redoing it. So I worked on .... slowing my ball speed down by lowering my ball in the stance.
Worked pretty well; threw 14 in a row and left a rock solid 9-pin the 15 ball. Throwing my old 3D Superhook - '98 vintage. I've been using it the past couple of months - I really like the way it revs up and its continuous backend - if I don't throw it through the breakpoint!
I've been in a slump for a couple of months even though I've thrown a couple of 700's during that period, it hasn't felt right. I've been training myself to get more kneebend and getting a stronger base for my release, keeping my hand more behind the ball - leading with the ring finger per John Jowdy, making sure I'm seeing my target at the release, blah, blah...
The main thing that's been causing the unsure feeling has been my speed overshadows my rev-rate - my swing has been forced. Sounds like you have the same problem and everyone that replied had great answers.
Relaxed, smooth, unforced, pendulum armswing; smaller arc; slower speed!
Hold it lower in the stance; focus on your target; allow your subconscious to bowl!
Dave