Personally I would have done the same thing as you. If you would have been low and shot it in the butt the bullet could have stop in the gut and then you would have had a wounded bear on your hands. Maybe you would have cut an artery or it would have reached the lungs if you were lucky. Maybe you would have head or spine shot, but if you didn't feel comfortable with it then you did the right thing.
With two bears in your sights in two days I would say that you are already successful. More successful than most hunters and if I were in your situation I would be one happy hunter seeing what you have.