1. Do a lot of dry-firing.
2. Do some "ball & dummy" practice. Go to the range with a low-recoil rifle, and take a buddy with you -someone who can load the gun for you without you being able to see what the person is doing. They hand you the rifle, and you aim and fire it, without knowing if the person actually loaded it, or handed you an empty gun! You aim and fire it as if it were NOT loaded, just as you did when dry-firing it.

After a couple of "ball & dummy sessions", I'll bet you will be able to keep your eyes open, and squeeze, rather than jerk, the trigger.

I've used this approach to teach some of the worst flinchers to shoot the .45 pistol well enough to qualify! It is embarrassing to be flinching and jerking the trigger with an empty gun!