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

Remove the cancer. It is an unusual diagnosis, but if you have cancer in the intestine it needs to be surgically removed. Depending on the type, other treatment such as chemotherapy or immunetherapy might be required. Continuing to stay healthy by working out and eating well will help you recover, but they will not substitute for actual removal of the cancer.
Follow doc advice. Ileal cancer is pretty rare to uncommon, except in crohn's disease; likely will need surgery, and perhaps chemotherapy. Depending on location, and amount of bowel removed, the nutritional and bowel consequences can vary. Other factors include "staging"-what is extent of disease re: lymph nodes, other tissues and organs. Get advice from GI doc, oncologist, surgeon, and rd (dietician). Good luck.