Chest Pain and Shortness of Breath: Is it a Medical Emergency?

SOS. I went to the ER last night after having growing chest pain that became drastically more severe. I also had shortness of breath and difficulty speaking. The nurse thought it was a carotid dissection, but the CT scan of my neck came back normal. She gave me prednisone assuming it was MCAS inflammation. Today, I have INTENSE burning in my chest on top of the already-established chest pain. It’s somewhere between the worst heartburn ever experienced and lighting the inside of my chest with a match. Is this a normal side effect from one dose of IV steroids that occurred 24 hours ago? Or could this be an aortic dissection (maybe it was too low to come out in the scan?)/should I go back to the ER?