Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to review your history and examine you personally, I cannot comment on the cause of your symptoms. However, I will try to provide you with general information regarding your problems.
You have multiple symptoms that may or may not be connected, and are not specific for a single condition.
Headache is a common symptom, and several conditions can cause it. The most serious conditions such as brain tumors and structural abnormalities are ruled out with a completely normal MRI, as you described. Glaucoma is a consideration specially if you have eye pain and “pressure sensation”, and you should see an ophthalmologist to check the intraocular pressure and find out what is going on in there. Other condition that comes to mind is migraine. Migraine headaches are characterized by usually disabling and very severe headaches, usually pounding (but not always), more pronounced on one side, with visual symptoms, nausea and sometimes vomiting, with relief when the patient goes to sleep, and the patients say that light and noise bothers. Specific treatments for the headaches and to prevent them usually improve patient’s symptoms.
Giant Cell arteritis or temporal arteritis is more common in older patients, but certainly should be considered. Specially since you have jaw pain, pain when you eat, neck pain, and unilateral headaches with some eye symptoms. History and physical examination are helpful, however sometimes blood tests are required (Sedimentation rate), and sometimes even a temporal artery biopsy. However this should be considered depending on the context of the whole problem, and you should discuss this with your physician to see how much testing is needed. If you develop visual loss in the context of GCA you should seek medical attention urgently.
GCA is occasionally associated with another condition called Polymyalgia rheumatica, which manifests by muscle aches, and sometimes proximal muscle weakness. Again, I am not sure if the kind of symptoms you have and the findings on your exam fit this diagnosis, but should be considered.
Regarding your palpitations, I cannot really connect this with your other problems. Palpitations are nonspecific symptoms and could be related to various conditions, ranging from heart problems to anxiety and panic attacks. Regarding this, an comprehensive evaluation should be helpful, and if required, an EKG.
Regarding your question about a blood infection, this is not likely in your case. Patients with infection in the blood (septicemia) get sick within days or as short as hours and minutes, with very high fevers, low blood pressure, and a usually require urgent hospitalization.
As I said, without the ability to take a history and examine you, I cannot tell you what you have. I think you should discuss your symptoms and concerns with your physician, to try to obtain a diagnosis, and if GCA is considered, start appropriate therapy. As I said also, with your eye symptoms I would suggest that you see an ophthalmologist as well.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.
my doctor is going to be testing me for a rare condition called acute intermittent porphyria.