Your problem, most likely, can be resolved by serious snapping in (dry fire). Here is the method that I used when I shot on several Marine Corps pistol teams. Remember, our endeavor is for you to take control of your pistol. I stood about ten feet from a blank white wall. I used the back of a kitchen chair to simulate a firing line. I practiced with different hand griping and trigger finger placement. The human eye can only focus on one point at a time. Some shooters focus their eyes on the front sight and some focus them on the rear sight. Then I take a firm grip on the pistol focusing my eyes on the front sight and raise the the pistol to eye level. You can see if you don't release the trigger without the sights moving out of alignment. If they move most likely you are forcing the shot which is not conducive to good accuracy. Experiment by gripping the pistol and the trigger finger placement until you get the trigger releasing without distrubing the sights.
The pretty picture book diagram of the target, the front sight, and the rear sight lined up perfectly clear doesn't happen If you are shooting with sight alignment the target will blurr.
Clifford L. Hughes