Hello John,
I sleep pretty good considering the dry mouth and stiffness in my neck each day and night. I do wake up several times, sip some water and return to sleep fairly quickly.
As far as the thought of cancer returning, which I am reading in your post, there isn't a day that goes by that I don't think of it. We all have been down a rough road. There are no guarantees given by our Doctors. The chances for us to get cancer again are 50% more likely once we get it. You and I could worry ourselves sick by reading all the numbers on the internet.
I can only suggest this to you. You have walked down a bumpy road, make a turn and find a smooth one. Meaning, enjoy your life as much as you can, because we can't perdict what will happen in the next day or week. I know a woman that is a friend of my wife's. She was told she had Stage 4 ovarian cancer and she needed to get her things in order. They gave her roughly 2 years or less to live. That was 6 years ago. I can tell you, she is enjoying life.
So, hopefully, you will control your thoughts, think positive and try to enjoy as much time that any of us have on this planet.
Take Care of yourself and my Best to everyone here