This is a actually very common problem. We all have a dominant side. I am guessing you are right handed? Is that correct?
The best way you can fix muscular imbalances is by training with unilateral movements. That way each side of your body needs to work equally to lift the weight. When you lift a barbell, your dominant side can take over and do the majority of the work. With things like dumbbells, each side is forced to work equally hard.
Take chest for example - For the next couple of weeks, swap out all your barbell pressing movements for dumbbell movements. Instead of barbell incline bench press, do dumbell incline bench press etc. I would also do a couple additional sets with a pressing machine on JUST your left side to help fix the imbalance faster.
Do the exact same thing with bicep, tricep, back, and shoulder exercises.