Self-discipline and self-control are the key ingredients in becoming the best hitter you can be. The best time to develop good habits is in practice sessions. Always practice as if every swing was in a game situation. This way you will avoid developing bad habits that will be hard for you to break.
Even the great hitters go through slumps. It is how you handle this period that will make or break you as a hitter. Giving advice and receiving advice from team players or others who do not know your style won't help either. The only way to get out of a slump is to check your hitting mechanics. Usually there is a problem of not keeping your head down. Concentrate on driving the ball right back at the pitcher. You need a target and he is the closest thing to you. Be patient, always be confident and things will come around.

Constantly striving to improve is important. To do this you must have an understanding of the essentials of good hitting. Remember, baseball is a team sport and good hitting is doing what it takes to help your team. By doing things like sacrificing to advance a runner, taking a pitch, etc. are signs of a good hitter.

Having the fear of being hit by the pitched ball is very common, especially in the "Lower Levels." During practice sessions players can practice turning their head and back toward the pitcher. This can be done with tennis or rubber balls. This will at least help in protecting the more important parts of the body.

TIP - Define what kind of a hitter you are, power or contact. Stick with it do
          not try to be both.