Physicians only please, I need serious answers.  I lost 30 pounds without trying in a few months time.? I am tired, get night sweats, I have lumps all over my neck. I feel weak, I can not hold things without dropping them.  I have passed out twice and went unconcious once.My husband had to keep my airway open.  prior to this event I felt like I was hearing them talk as if I was under water, I could not understand them, I did not go to the ER,because I work at one and felt stupid.  I have no added stress, I eat well, I do not have any mood disorders or eating disorders. Per a psychiatrist. I weighed 120 went to 91, I started gaining weight and now I am loosing again. A doctor at the Mayo said he thought it was a rare virus that causes "unexplained extreme weight loss"  just eat more. I get short of breath and feel like my heart will beat out of my chest. I am scared it is cancer but the couple of physicians I was referred to treated me like I was a blonde who was not eating and would not look for other causes. I am scared and can feel something is very wrong. I would appreciate any help.

Summarized question: What are being tired, night sweats, lumps all over the neck, feeling weak, going unconscious, and unexplained extreme weight loss symptoms of?