W is open to C. The A with OM is winding down. Now is not the time to bail. If you need to take a couple of days away, do it. But don't act rashly now. Be patient, detach.
I've NEVER seen an A end on these boards with a clean break. There are ALWAYS several slips, more and less extreme. But W being open to C even after your snippy remarks is HUGE.
Rather than moping about what some OM says who W will come to despise in time says about YOU, take it as a challenge. BE the person you want to be in a healthy vibrant R. Be independent, Be confident, Be happy.
If you are finding it too damaging to be a doormat, don't be a doormat. Doormatting is always a bad idea. Set some boundaries. Stop doing things that hurt you. But try stepping back, detaching, giving W some space. She is emotionally going through a lot of what you have and she gets to combine that with shame for the A. She'll be all over the place. Don't take it personally.
