Stress is a common condition that we all experience. Stress can often be good (known as eustress) as it motivates and energizes us. However, in some situations, it can be harmful and burden your body. I would recommend that you talk to your doctor
regarding this. Your primary doctor can help determine the cause and potentially treat this problem.
Firstly, there are many things besides stress that should be ruled out by your doctor. Without more information, it is hard to know exactly what the problem is -- but numerous issues could be in play. Muscle disorder, nerve disorders and even bone problem can be an issue. Often people in your profession can suffer from vitamin deficiencies from specific diets used while training -- and these often can affect your nerves. In addition, stress fractures of the bones are common as are hormonal problems (like thyroid). Talk to your doctor about this.
Assuming these readily treatable issues are not occurring, stress may be a factor in your lack of precision. However, this to can be addressed with the help of your doctor. I would recommend that you see him or her to discuss this. Some people also benefit from talk to a psychologist
-- who can help with stress management techniques or even medicines. Good luck!