You are not lone I'm experiencing the same thing especially left arm pain I have all of those symptoms and it cause me to be scared at night to sleep because I think that I'm going to die from those symptoms which make me panic even more I need help as well
This definitely sounds like anxiety. I too suffer from anxiety about dying. I have had anxiety attacks over thinking I have brain tumors, heart attacks, strokes, diabetes, allergic reactions, the list goes on and on. For me, I have to take control of my fears, so this might help you. Accept that what you are experiencing is not a brain tumor but anxiety. You will not die from the anxiety and it will not harm you as long as you can accept that this is what is causing your symptoms. Anxiety can cause one to believe they are experiencing symptoms anywhere from a brain tumor, to a heart attack, to stroke. Only to find out that they are perfectly fine and that its all in their head. I believe that you are experiencing anxiety symptoms not brain tumor symptoms.