Hi, welcome to DS!
Infectious disease doctor can rule out things such as lymes disease and other autoimmune diseases, so that would sound like a good start!
I and many others also have a rhematologist.
You didn't say whether or not you have been diagnosed with CFIDS. I will assume you have been.
Once you know what you have, I guess doctors really arent much help! We have to kind of learn to listen to our bodies and get guidance and advice from other sufferers. The doctors really don't know alot about CFIDS/ME and often tell us to seek mental/emotional help, just not believing that we have a real physical illness. Don't let this happen to you.
First, the right doctor, GP, whatever, one who believes in your illness and has ruled out anything else that could cause the fatigue and then support to help you get on with your new life.
We're here to help!
Join in! Ask questions. We want to help you.

Darla give good advice. I would say ditto to everything she said. I would add that I have gotten the best support and treatment from a nurse practitioner in an alternative (or progressive) health clinic.

I too like what Darla said. I have yet to get much help from physicians of any kind, other than the Fibromyalgia and Chronic Fatigue Center in Phila. He was the first doc to make me feel like my symptoms are very real; and that I am not imagining all this, or that I am mentally imbalanced. Listening to our body and paying attention; journaling and documenting really is helpful. I wish I could say that it does more than help you to know your limitations, and is a reference point when you need to give time lines, or symptoms to a doctor that is trying to help. I believe that there is sooo much that professionals do not understand about this disease/disorder. I truly believe that for chronic fatigue, for me at least, has more to do with hormonal issues than anything else. That makes it almost impossible to get help and healing. It seems that it is so individual and unique to each person's experience. I appreciate this resource of being able to find others that are having the same problems. I too am desperate to find help, and others that have similar experience.

A Rheumatologist deals with the understanding the immunology of the disorder, and are generally regarded as the auto-immune disorder specialists.
An Immunologist is a broarder group of specialists who dael with all aspects of the Immune system.
http://en.wikipedia.org/wiki/Immunology
http://en.wikipedia.org/wiki/Rheumatology
An immunologist will normally refer you to a Rheumatologist if need be.
Cheers
Ali5tair

Thanks for all the advice!!!