I work really hard to stay in shape and eat right. Now I have a diagnosis of chicken pox. What else can I do so that it doesn't affect my overall health?

Keep healthy. Generally speaking, chicken pox is a self limited infection that causes an itchy and uncomfortable rash and some other symptoms. Unless you experience a complication with it, it should not have any lasting effects on your health. Continue eating healthy, exercising, etc and you should be fine. The infection is worse the older you are so see your doctor if you have any concerns.
Not your fault. Contracting chickenpox has nothing to do with nutrition or physical fitness; it's a virus, you were exposed to it, you got it. No big deal. Though adults often get sicker with chickenpox than do children, it will resolve if you follow your doctor's instructions, and chances are excellent that it will not affect your overall health.