I've had episodes of acute anxiety regarding health issues. What I needed most at those times was a bit of breathing room so I could think rationally. Anti-anxiety medication calmed me enough so I could use cognitive behavioural techniques to dismantle my obsessive fears.

Can you speak with your therapist about medication options? You seem to be in a state of constant hyperarousal for which meds could provide much needed relief. I highly recommend The Anxiety and Phobia Workbook once you get to a place where you are able to start challenging your thoughts.
https://www.amazon.com/gp/aw/d/16262...ob_neva_mobile

What you're going though is so difficult. Try to remember that the physical symptoms you describe are manifestations of anxiety. I hope you find relief soon.