2Blade, I get into the same habit sometimes.
Someone suggested to me to draw and come to anchor and just hold for 2 or 3 seconds while aiming at the target, then slowly let down, then repeat 3 or 4 times. Then, once you've relaxed somewhat, do the same thing, but this time after the 3 seconds, release.
This method really seems to help me get out of the snap-shooting rut that I get into sometimes.
Just a suggestion. Hope it helps!
C