Dawn Huebner has written books to help children with this sort of thing. We have "What to do when you worry too much" and there's another that I haven't read called "What to do when you dread your bed".
My 9 yr old is suffering from many anxieties including dislike of being alone in a room and fear of the dark etc. in a different post I detailed some of the anxieties and it was kindly suggested that I post a separate thread asking for recommendations for reading material. Please do let me know if you can offer any help. Thank you.