I had a bad flinch as well. This is how I minimize it.
Dry fire, A LOT. front sight in perfect focus, Zero movement when shot breaks.
Got one of those laser snap caps. When the shot breaks, the laser should be a pin point spot, not a streak. That'll tell you if you are gripping, slapping the trigger, or something else is disturbing the gun when the hammer falls
Have someone randomly load snapcaps in the mag for live fire. When the gun goes click, you'll see exactly what's wrong.