I'm sorry you are still going through this. I too am just finishing up my 5th period post mirena and have definitely been experiencing a crash. I didn't suffer any crash at all at the 4th period, but this one has been bad.
My anxiety is back with a vengeance and my mood has been so up and down. It is so frustrating. I thought I was finally getting through the Mirena issues, but they just keep coming back. It probably doesn't help that I have been extremely stressed out this past month too.
Have you noticed if stress triggers any of your symptoms?