I am stunned to hear that you have been dealing with something this serious after having had the Mirena for such a short period of time. I had it for just 5 months and after removal, went immediately into menopause. I am 43 so while it's not "premature', it is early. I had been having normal periods prior to Mirena. It does sound like your body is experiencing estrogen dominance, as you described in your previous post, as estrogen is what makes the endometrial lining build up. It seems as if your body just stopped making progesterone...but you've had a few cycles already, right?
I never heard of this side effect post-removal, either. I am hoping that things settle down for you and that your body will get back to normal. I'm so sorry that you are having to go through this. All we wanted was a safe, effective form of birth control.....no one ever mentioned things such as this. Take care of yourself.
In answer to your question, I meant to add that I never got another cycle on my own after the Mirena removal. Two days after removal I had 2 days of only slightly heavier than spotting bleeding and that was it. But obviously my body wasn't producing much estrogen on it's own....bloodwork (when I started having hot flashes) showed that my estrogen was almost nil.