"How much more of this torment am I to endure?"

I have suffered terrible headaches for a few years (4/5) almost certainly worse in the last two years. I have been told by impartial advice that the condition is caused by some medication I was on which caused nerve damage, due to prolonged exposure. Although my condition can have some related illnesses that can cause these headaches, there seems to be very little provided in the way of tests, or any kind of support, be it pain management or otherwise.

Personally, I feel that there is a considerable degree of bias against me as a patient which is directly responsible for my appalling treatment. I have and still am suffering with these sometimes terrifying symptoms, but feel ignored and neglected care - wise, and am struggling to get even close to any answers which I feel will only be provided if I have tests in Europe or somewhere. I feel singled out as a problem patient and that the doctors who were entrusted with my care have wilfully chosen to do so because they are seemingly biased. Question is: how much more of this torment am I to endure? All the tests for this condition which are located in one area (which makes it easier to test for) have not been done. I find this despicable and totally negligent and unacceptable.