I published a homepage called Healing Dreams, looking for other CFS patients also interested in dreaming. Sleep problems are a factor in CFS and especially in fibromyalgia. Two years ago somebody published rather preliminary research results that suggested that fibromyalgia patients have a flaw in the quality of their sleep similar to elderly people, skipping the parts of the sleep that produce growth hormones. I never heard anything from it since. I think you have to be very careful with experimenting.
Some people suggest to use melatonin.
Recent British research suggest that CFS is caused by too high levels of melatonin. At the Dutch CFS mailing list this naturally upset quite a lot of patients who thought it was a innocent miracle drug. Use some kind of bed going ritual, etc. You probably know all these things already. As to too much dreaming, I doubt if that is really a problem.