Breaking bad habits

Tracey Baumann highlighted my head movement when breathing left (preferred side by a mile) during our last session.
I confess sometimes I need a bit of time to figure things out after a session.  
Today swimming a bunch of sets at 1.0 and below, I was two strokes less breathing right.  I don't breathe nearly as comfortably this side but my head snaps back into place better possibly through rotating a little less to breathe that side.
When I focussed purely on keeping a still head when breathing left I dropped a stroke and noticed it was still not as stable as when breathing the other side.
It's amazing the difference a still head makes.
Breaking bad habits is never easy.