I am tying to eat properly and exercise more. If there are any nutritional supplements that you know of that might help me, I would appreciate hearing about them."
It seems lifestyle can have a large influence on progression of PC as suggested by the relatively low instance in Japan and some other Asian countries.
To briefly answer you question on supplements, suggestions include Lycopene, slenium, vitamin E, vitamin D3. Fish Oil. Most of these are available in the diet or naturally, but supplements are suggested for PC patients.
Dr Myers in his books suggests a mediterranean diet, and reduction of red meat and dairy fat consumption.
Soy and green tea which is widely consumed in Asian countries is also often mentioned.
More extensive information is available online or in the books by Dr Myers or lifeextension foundation (lfe)