"my wife just started having severe bleeding and sharp kidney pains. tonight she told me that she was so fatigued that she couldnt even drive to go to the ER."
not normal, nor should the mirena move.
She should at the very least, check to make sure she can still feel the strings.
everything you are saying indicates she is reacting badly to the hormones. It only gets worse. being diagnosed with post partum is extremely common, as are the other symptoms.
I think it is great you are here. wish i could give you birth control advice-but my hub is snipped (all done w/ babies). Best of luck to you both.