That is quite a list of symptoms, and I am so sorry to hear that you have been suffering through so much. If you have a headache and a stiff neck, it is important to discuss this with your doctor
if there is any concern for you having an infection in your brain or nervous system. Meningitis is uncommon, but there are some people who may be at an increased risk (due to previous surgeries or infections). Speaking with your doctor will help you to know if there is something more that you should do now.
With regards to your other concerns, and the long time that you have been treated for these other symptoms, it may be appropriate for you to seek help from a specialist. Infectious disease doctors
are often helpful with infections, and rheumatologists
are especially adept at treating symptoms that are seemingly unrelated but affect multiple organ systems. If your doctor feels that it is appropriate, a discussion with either of these two specialists might be a good way to help you get some answers. It can be frustrating for patients and doctors when diagnosis are difficult. Please speak with your doctor about your question.