Can you post a pic of your target?
Most problems with pistol shooting are
Staring at the target instead of the front sight..more so when shooting at close distances
Poor trigger control
Poor grip technique
There is no "trick" to master focusing on the front sight. Something I get students to do is go through a mental "ckeck list" just before they shoot. "front sight, front sight, squeeze, squeeze, front sight, follow through.
For trigger control, once you start squeezing the trigger, don't stop. Some people will focus on the hammer to try and anticipate when the shot will be fired. This does a couple of things.
The obvious is..you aren't focusing on the front sight and people have a tendancy to "stop / go / stop / go with the trigger pull because they glance at the target and realize their sights aren't where they should be.
The other part of trigger control is..DO NOT release the trigger until the gun comes down out of recoil. Doing so before will cause the barrel to move before the round has left it.
As for grip..you should be holding the pistol with your strong hand firm enough so it doesn't jump out under recoil but DO NOT squeeze it so hard your finger tips turn white.
It doesn't take much side pressure to throw your shots off left or right.
You want any pressure to be on the back strap of the grip and the front, not the sides.
If you use the thumb over thumb style grip, gently push forward with your stong hand and pull back with the same amount of pressure with your weak hand.
You don't need a Hulk hogan grip on your gun. I force the finger tips of my stong hand into the palm of my weak hand to ensure I'm not putting side pressure on the grip.
To get ride of your flinch, I'd use a rim fire pistol or revolver for a while then go back to center fire.