Years ago when I was shooting completive, I shot a match in Shreveport, LA. On my left was the “Distinguished Master, Jim Clark” (also one of the finest pistol-smiths I ever met.). During a discussion in the practice session a gentleman approached him and asked about a similar problem, Jim’s answer stuck with me to this day, he said, “try to train yourself to cut a small sideways figure eight over the target and learn to squeeze the trigger as you reach the center of the figure.” He demonstrated with a .45 and to everyone’s surprise, with the gun moving, he cut the X ring out of the target. I later ran across the gentleman and he told me he was not back to the completive form he once was but that Jim’s hint had helped.
My hand is not as steady as it once was, I have tried Jim’s suggestion and it seems to help, I think spending some time dry firing at home might help to.
Give this a try and give us a report if it seems to help.