It's common with cancer, due to the chemo, maybe radiation for that matter, but also with all the concerns on your mind about cancer, treatment, recovery, and you probably don't have the same physical, and mental activities, contact, you did before cancer. Also, take a look at what medications, even OTC products, you are taking that may cause sleep disturbances. Some even have caffeine in them. Discuss this your doctors too. They have medications to help sleep like ambien, and OTC products like melatonin, camomile tea. Try eating some carbs at night, which makes you sleepy, hot shower, warm milk. Light exercise may be helpful, such as walking, and for relaxation some try yoga, tai chi, meditation, massage. Try to stay away from Tylenol products, which interferes with he liver's detoxification cycle, and cause liver toxicities.