feeling bad? My son is close to your age and has had some of the same symptoms. remember going through that when I was young too.
Many of your symptoms like the head and neck pain, the shooting pains, anxiety, fatigue can be caused by nerve interference. A chiropractor can correct the nerve interference and he should be able to tell you if that is what is causing your problems or if you need additional help. Also, when you are thin you can feel the lymph nodes in the groin area, and neck. They feel firm because that is their natural state when not swollen. Also if you began with a virus and it attacked your nervous system as they often do the anxiety will heighten even more. It isn't unusual for this cycle to go on for several months as yours has. Maybe you could try a chiropractor. Most here wouldn't recommend my second suggestion, but if you are having major health anxiety, it may not be a bad idea to go to a psychiatrist for a short course of xanax or other anti-anxiety medicine. To relax for a while may be very good for your body, particularly your adrenal glands which can become exhausted during prolonged stress.