I carry a bottle of nitro with me everywhere. I really believe it saved my life one day while up a canyon, and down my way back to camp. I could hardly breath right, but what a life saver. You spray it under the tounge. Thank goodness I had it in my pocket while walking around up there. Yes, and what a headache. Got to the ER, they kept me and did all the tests for a couple of days, then went back for an ablation..my second.
Still hoping you find the reason for the chest pain.
Take care, Cynthia