Pins come out today, yes?
Left hand accuracy depends upon the same fundamentals you first learned with your right side, but you need to give the left hand an opportunity to learn them 'cause they involve a different part of the brain. (The right side of the body uses the left half of the brain, and the left side uses the right half of the brain). The reason most of us have a dominant side is that less brain "hard drive" is used. Ambidextrous people take up more brain space with motor skills than those with a dominant side.
Dry firing and practicing the presentation work just as well for the left hand, and because you already know the "right" way to shoot right-handed, you can avoid the bad habits you learned with your right hand when you first started shooting.
A fine-motor skill like shooting or tying shoes requires 2,000-4,000 repetitions for it to become learned. Once learned, it gets stored in a deeper, lower portion of the brain. When first learning, we use the frontal lobe and the sensory-motor strip of the cerebral cortex because we have to concentrate our attention to get the skill smoothed out. Later, a learned activity/skill requires only subconscious rather than overtly conscious concentration to be performed.
Have you lined up a therapist yet?