When you are having one of those rounds where nothing is going right, and you feel you have "lost your swing," you need to get back to the basics.
Remember two simple things, things we are told when we first pick up a club when we are beginners, but they are oh so easy to completely forget:
1. Lock your eye on the ball, with real focus
2. Swing slower
That's it! These are two critical factors in your swing. If these two things are not done during the swing, you will be completely out of rhythm which can result in a multitude of bad shots. Everything such as slicing, hooks, hitting it fat, thin, topping it, hitting it off the heel, the toe, etc. it goes on.
Both the focus and reduced swing speed greatly increase the chance of solid and square contact. Additionally, this is a very doable mid-round correction and will stop the bleeding on a disastrous round. Keep this in the back of your mind whenever you play.