I truly understand how horrible it is to wake up every day with feelings of angst rushing through your body, it can certainly set you off on a rough day due to aftermath of the anxiety attack.
I started feeling the same thing a few years ago, I always had difficulty throughout my life with anxiety disorder or panic attacks, this was different because the attack felt different, I always described it like a sense of trepidation, kind of the way you feel when waking up and you have a scary appointments coming up. I mentioned it to the doctor and he thought it might be from my medication wearing off overnight, it's possible but I don't think this is the answer. I don't know of any cure or treatment for this but my Ativan does make it subside so I'm happy for that. I still get them even when my tests come back as stable I can go through this uncomfortable event. My own theory is that I believe it's from all the negative events going on in the world and we're living through it never really knowing what tomorrow will bring, this is even more so when you are going,through health problems, it's just too much sometimes.