I don't know if I've changed the type of Pots I have, but a lot in your description sounds like your now having panic attacks ( "impending sense of doom") or at least much increased anxiety. I also have been prone, especially at certain points in my life, to getting panic attacks. Admittedly for me it makes my bp drop not increase, but autonomic dysfunction is individual. I also have been more prone to attacks when I'm most feeling unrelenting anxiety about my illness and myself and appearance ( going out in public, looking ill). It's hard to be out in public feeling like you might not survive this outing and not feel your anxiety about your illness overwhelm you, and feel separated from the normal people around you. I don't know what's happening with you but I think maybe your anxiety has increased a lot?