Physical therapy is a very useful alternative therapy for many people with many different chronic illnesses. Being able to work on-on-one with a therapist in getting physical activity is not only motivating when the pain can be too much, but helpful because medically they will know limits and where to push you as well.
When looking for a physical therapist, keep in mind many are only skilled with treating acute injuries. From personal experience I know this after having a bad experience with a physical therapist who knew nothing about Fibromyalgia. Try asking your doctor to recommend you one or call and ask to see their background with treating chronic illnesses.