I think something is wrong with me?

Yes honey, you have ocd. I have had it for about twenty of my twenty-eight years on this planet. All the worrying about getting cancer and stuff is the ocd too. It is your mind obsessing. You should call your local mental health facility and ask where you can find low cost help. Don't be afraid to take medication to help relieve the anxiety you feel all day, every day. There is a book by Fred Penzel, Phd. Called Obsessive Compulsive Disorders; which will help you a great deal. It is published by Oxford press. Best of luck.