Please go to the ER and get tested for blood clots in the lungs. (pulmonary embolism) These are the EXACT symptoms I had last week and almost died because I was misdiagnosed due to otherwise being completely "healthy." But if you really are having these symptoms, do not wait another minute., Go and get a CT scan of your chest. Accept nothing less because x rays do not pick these up and blood tests can even fail to show enough symptoms. A head CT would not show this either. My blood test as I laid in the hospital was only slightly too high in only one category, and they said it would've been overlooked if that was the only test I had. CT scan with contrast is what you need to truly rule out PEs. And they are so much more common than we are lead to believe. I have a handful of friends who are now coming to me with their stories and we are all young and healthy, male and female. All symptoms sound exactly like what we all have experienced. I would shoot upright in the middle of the night for a couple weeks before treatment and felt intense panic and anxiety, unlike anything I've had before. I kept joking with my best friend that I thought I was dying. I had intense, deep fear that I truly was dying, but I still brushed it off at first. Breathing was ok too right up until a huge clot broke off and blocked my lower right lung. I now have permanent damage from it, but thankfully that happened or else I may have never gone back to the doc until it was too late. It happens to the best of us! Please get checked out again. Your gut is telling you something is still wrong and blood clots are some of the most missed issues in healthcare. If you have already been to the ER 4 times, this is proof that something is terribly wrong. I'm surprised they haven't already done a CT scan of your lungs! Of course it could be something else, but this needs to be ruled out asap.