How Can Body Ache, Backache With Shoulder And Neck Pain Be Treated?

Hi, I am unmarried girl of age 27. I have a problem of bodyache mostly backache, shoulders, neck etc. And I am not putting on weight also though my diet is proper, I am very thin. I have consulted many doctors but no relief. Had tests also but reports comes out to be normal. And every time docs advise me to take Vitamins and calcium. But I don't think that's the problem. I have problem of acidity also sometimes. I think this is related to that but don't know. Please advise me what to do. Thanks, Manisha