picture yourself making good contact with the ball and having a good hit, think about what it is that made you hit the ball well, and then when you go up to bat, dont think about your mistakes or how you have struggled lately, just focus on the details that you just pictured, and if you focus and follow through with what you pictured chances are you will be successful. thats what i try to do for every sport i play. ohh and just focus but do what you have to do to relax. dont put too much weight on your shoulders that you absolutely have to hit a long ball or that you must get on base because chances are you wont be relaxed and as a result not successful (which is your case and most peoples cases) Dont think about the pressures at all, just think about making good contact and focus really hard on it and good things will happen.