Two things: 1, I would be careful with supplements? my mother's regular doctor called me in a panic a few years ago because her annual kidney test came back bad. then all the kidney specialist really did was take her OFF all the supplements my brother had put her on (and he yelled at me, cos he thought I was responsible! ha, like she ever listens to anything I say!) and that did fix her kidney problems, thank god, cos usually once your kidneys start going, they don't come back. and supplements are not inspected at all.

I got tested for heart palps, and honestly the only time they come back is when my mother calls me. I am not really in touch with my feelings at all, but she must have really scared the crap out of me when I was little, is all I can figure out. so I would guess that something similar might be happening with you, losing your job is bringing up a fear and insecurity. I got fired, I say "for the last time" ten years ago, but my whole 30 years working I felt insecure and never stayed at one place very long. And being called into a boss's office started the heart palps.

anyway, if the tests you had came back clear, I would trust them, and chalk it up to anxiety, even if it doesn't feel like your "usual" anxiety. that's my problem, I don't want to feel my feelings, but my body knows they're there anyway.