Without belittling how potentially an A can magnify the task at hand,it is out of your control. Regardless of what is happening with W you have work to do on you for you.
Start by those problems that you mentioned. How did you contribute to the downfall of your M? What your W considers as your faults is probably more important to concentrate on, because it is not going to: improve until her perception changes. List your faults and plan how to remove them.
It is great that you stand up for yourself and was tactful to wait until ye were alone to discus what you viewed as inappropriate.Do not allow her to disrespect you. On that point it is very easy to go overboard and crack the whip for every little misdemeanor, which may make you feel better/stronger but can quickly become ott and create worse problems than it solves. Some th ings you need to let slide for now. Use good judgement to choose your battles but don't walk on eggshells either.
It is good to note what you have achieved so far. It helps also to build on that and review goals regularly.
Keep posting and more help will come.
Best wishes
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together