I feel for you so much! I am nearly in tears because I know EXACTLY how you feel having experienced it recently. I think most members here know that feeling too. It makes me so angry and sad at the same time. I hope you can find a better doctor. I have a pain doctor who believes me but ny GP gives me the impression that he doesn't. If he ever voices that to me I will ask my pain doc to call him.
About the losing weight thing... One of the papers I print out says that losing weight will not effect the pain.
Diagnosis and treatment: The Dercums Disease diagnosis is based on what the patient tells and what the doctor finds at his examination. There are no tests to take, but some blood samples can show signs of infection and/or that the immune system are very active. The doctor can also take blood samples in order to exclude other diseases. The knowledge about the disorder is not well know and many patients are poorly treated. The treatment of Dercums Disease patients is inadequate. Attempts have been made to get patients to lose weight, but it is extremely difficult. If the patients succeed, the weight loss has little or no effect on the symptoms.
Source:http://www.emergingworlds.com/ch_conditions_detail.cfm?vPageid=157