It's a good practice to mentally play a round in your mind where you control the ball and place it where you want it to go avoiding all the problems such as water, out of bounds, sand, etc. Try it sometime and let your imagination run wild.

Take notice of this mental exercise to see if you allow bad thoughts to enter your mind even in your pretend round.  Bad habits die hard and the first place to attack them is in your conscious mind.

In order to eliminate bad habits that you have formed in your game try this 3 step process:
 

1.       First confront your fears in your game and admit them by writing   them down on a piece of paper.

2.       Replace it-it's time to trade in bad habits and negative behavior for good ones.

3.       Stick with it-by being persistent, diligent and remaining disciplined your game plan you'll be soon forming a new habit.

We can't change our circumstances about how the ball bounces so to speak, but we can alter our response to them. It's all about choice so choose wisely. Having a brighter outlook about playing and excepting occasional bad breaks that are inevitable will help you start getting over being "Teed off" about yourself and your golf game

However, sometimes losing your cool can be good because it can help you let off some steam and help you refocus on the task at hand. Often, as all golfers know we keep it bottled up which can impair our performances for the rest of the round.

The key is to allow yourself to completely vent, then refocus again immediately. By venting I don't mean throwing or breaking clubs, or cursing. The skill of refocusing lies in knowing what the most important element to master is. How does a person learn to regain composure after losing it?

Just remember that losing your cool is nothing more than focusing on what went wrong, and allowing yourself to get frustrated, angry, ticked off, etc. Think about how you respond when you’re angry