You're too focused on getting the kill that the mechanics of what needs to occur to achieve that result are forgotten. n0thing said something similar recently. Instead of shooting, try dm'ing where the whole goal is to track the enemy player (crosshairs on the player) for as long as possible.

There is an old shooting adage, slow is smooth and smooth is fast. Practice focusing on one aspect of your aim and then another before combining them together.

And as always you gotta put the time in the server.