I'm so very sorry that you are having to go through all of this craziness, knack!
Unfortunately, Lyme is exactly like what you describe when it's not being treated. The body is doing it's best to mount a defense, then it gets overwhelmed once again by the shear numbers and complexity of the bacteria.
Also very unfortunate is that you have found yourself caught between the Lyme literate and the non-Lyme Literate worlds. One side tells you that things are okay, no big deal, and the other side tells you that it's all connected and needs to be addressed.
I, of course, stand on the side of treating - or at least addressing - all the things that are "off" in the body so that it has the best chance to defend and repair itself.
Sticking with that, personally, I would really encourage you to not wait any longer to get started supporting you thyroid function. TSH isn't the best way to measure thyroid function as it often misses how well the thyroid is actually converting & using T4 and T3. I know I've posted this site a hundred times already, but it's the best one I found for both thyroid and adrenal function information. It really makes sense of the T3, T4 and TSH, as well as adrenal tests:
www.stopthethyroidmadness.com/With all of that being said though - I would encourage you finish out with the monitor - heart issues scare the beejeebers out of me (!!!), and they are quite serious. So getting the all clear is a good idea. It's not like you aren't doing anything to help control/treat the infections during this time.
I do hope that you hear back from the Cardio office soon. How terribly frustrating -
resubmit the question??? Ugh!!!