This is what seems so real about this game. I fall into streaks where I swing at everything, or start swinging for the fences. Sometimes it works, sometimes I just strike out a ton.
What works for me is to shrink my strike zone. When I expand it I start swinging at everything: pitches way too high, big curves that practically hit the plate. When I hold back and make my strike zone small, I might take a few strikes, but the pitches I do swing at are much better. Swinging at better pitches leads to better contact and less strike outs. Just gotta find what works for you.