fibromyalgia is what doctors call a 'functional' disorder, like irritable bowel syndrome. 'functional' basically means that there is no specific abnormality to find on any test which is available and that there is a large psychogenic component to the symptoms, meaning that certain personality types tend to have this kind of disorder and that anxiety and depression tend to make the symptoms worse. It is often a self fulfilling prophesy as if you worry about the pains then they get worse and when this happens you worry more. It usually affects women in early adult life.
It is also made worse by sleep disturbance and sufferers don't get the normal amount of REM (rapid eye movement or 'dreams' ) sleep. You can give the symptoms to non sufferers by interupting their sleep in experiments.
The condition tends to recur and can last for ages but it is entirely harmless other than being very distressing.
In terms of treatment, exercise programmes are said to be very helpful as trained athletes are the only group who they couldn't give the symptoms to in the experiments they did interuppting sleep.
Also, any measure to improve the sleep you get is said to help. (I know, I know ) Amiriptyline taken in very small doses at night is particularly useful (A sedative antidepressant, NOT whilst pregnant and best AVOIDED if breastfeeding although not totally banned)
Heat treatments and massage work, but pain killers and anti-inflammatories (ibuprofen etc.) don't
Some people find steroid or anaesthetic injections at the trigger points also help.
Trying not to worry about the pains is difficult but they really should get better if you able to feel more relaxed and they will certainly get worse if you get very stressed. You will probably be able to look back and match up in your mind that the pains felt at their worst at or around certain other events that were going on in your life and stressing you out. In that respect it is very similar to IBS which lots of fibromyalgia sufferers also have!!!
Hope this helps.