Hi doctor, I fear of contamination and always afraid to touch things. My main problem is that I cannot meet cancer patients thinking them contagious.?

Not a Risk. Cancer is not contagious. You are more of a risk to the cancer patient than they are to you! if the cancer patient is on chemotherapy they may have some impairment of their immune system. It is futile to try to prevent all contact with bacteria. They are all around us and usually don't cause problems. If you have a cut, wash your hands and cover with a bandage. Wash hands if you have a cold or flu.