I was wondering if anyone had any tips for dealing with the physical symptoms of exercise that mimic anxiety.

I used to be able to push myself quite hard, but that all changed when I experienced my first panic attack late 2021 (unrelated to exercise). I'm in a much better place, but I find that I have to pace myself a lot more or else the anxiety becomes overwhelming. 

I don't necessarily feel like I'm going to have a heart attack, but I get a feeling in my chest that I'm not even sure I can describe. It just kind of feels like dread. Staying still usually worsens it, and I often find myself having to "walk it out."