Actually, she dumped you when she had the A and moved out of the house. You are finally responding correctly (IMHO) to that event. You are not ending the M, she is (by living elsewhere and continuing the A, she was still in that process)! You are just separating officially, to protect yourself. Who knows who will be the one serving the D papers?! That's a long ways away.
Thanks BeingMe, it's great to hear someone else say that.