Update, six weeks post-removal: I can't even find words to express how much better I am feeling. I was initially skeptical that my problems were caused by the Mirena, but count me a believer now.
I started to feel better a week after removal--fewer sleeping problems, less tingling in hands and feet, heart palpitations lessened and eventually went away entirely. As it happened, my appointment with a neurologist (about two weeks ago) exactly coincided with the start of what I think was my "crash," which happened eight days before the start of my second period post-removal. After noticing the heart issues (my heart would race any time I stood up from a sitting position, and my blood pressure would go up as well; this was stuff that had also happened pre-removal and was the reason I got the Mirena out) and testing my reflexes the neurologist told me that I was "hyperreflexive," said the B12 supplements could be "masking something" and ordered an MRI on my neck. Scared the crap out of me, especially because that night was the worst night BY FAR that I had had since having the Mirena removed--horrible heart palpitations/racing, horrible diarrhea, no appetite, couldn't sleep at all.
Anyway, it got much better after a couple of days and all symptoms went away COMPLETELY within about a week. I feel fantastic and I haven't felt this good in years. (I can do my normal three-mile run again, easily! A couple of months ago I couldn't run half a mile without stopping!) I don't know the results of the MRI yet, but I feel very persuaded at this point that Mirena is to blame for it all. And I think I was mitigating and hiding the neurological symptoms of the Mirena for years by taking B12 supplements. I am still taking the supplements for now--as well as vitamin D because I found out in October, when all the craziness started, that I was low on vitamin D--but am hoping I can lessen my dosage and eventually stop taking them. I can only hope that I will be mostly okay from here on out.
Given that a lot of women (including myself) seem to have a post-removal crash about a week before a period, and that this coincides with the "progesterone" part of the menstrual cycle, has anyone on this forum talked about the possibility that the neurological symptoms of the Mirena are caused by the artificial progestin hormone messing with the body's production of natural progesterone and its role in neurological health, including calming the nervous system??? Having read more about the neurological functions of progesterone (and the fact that artificial progestins apparently do none of these functions), it seems quite plausible to me that the crash I experienced a couple weeks ago was my body not having figured out the progesterone thing yet, absent the Mirena hormones. And that these artificial hormones, by messing with the body's production of progesterone, is somehow messing with important nervous-system-protecting things that progesterone apparently does. Is this too simplistic an answer???
Since my issues started (nowhere near as severe) when I was on an oral contraceptive (Ortho try-cyclen lo), I think that for me this is a hormonal contraception issue and not just a Mirena issue, though I think whatever Mirena does is somehow much worse. No more hormonal contraception for me!!!