From my personal experience, it is not unusual to have an ebb and flow in recovery . . . if you did not like your therapist, take a step back and ask yourself why . . . then, for the next therapist, and there should be a next therapist, "interview" him or her and ask questions . . .for example, perhaps you felt that this therapist did not give you enough time to express your thinking, needs, goals, etc. So, with the next therapist, ask him/her what his/her approach is . . . it is not unusual to go through a couple of therapists to find one that aligns with your needs so please do not give up . . . .
Even though your diagnosis of POTS makes it difficult to exercise per se, would you be able to go for a leisurely stroll a couple of times a day? Just to get out, do something different, get some fresh air, etc.? For myself (and I am just coming off of a speed bump in my anxiety management / recovery), I find mindfulness and soaks in a tub with Epsom Salts to help a lot . . . I have been "bad" in the last little while as I have been off eating properly and on a regular basis so I am now working my way back . . . I don't like speedbumps but I have accepted them as telling me something . . .perhaps your speedbump is telling you to return to your search for an appropriate therapist . . .
Please remember, though, that you had a month without panic attacks and feeling good and that is what you are working your way to achieving on a long term basis . . . eventually the good times become of longer duration and the not so good times appear less frequently and less intently but it is a process and not an event so you need to persevere . . . let us know if we can support you in any way as you get back on track . . . . I am confident that you will succeed but take one day at a time . . . .take care, kc