When is enough enough?

We had the hyperfocus thing in the beginning and she had so many wonderful qualities I asked her to marry me. Shortly, into the marriage (we only courted for about6 months and were engaged for 6 more) conflict began popping up. The pattern began in a 3 week or so cycle, Week one would be good, week two I would notice forgetfulness, mistake making, physical illness sx, and provoking behavior. Week three would be started by some conflict: her reacting to my reacting. She would always escalate the conflict and then withdraw into the bedroom for days each time. She would then emerge and want to (or actually did) forget the whole thing. Never trying to repair the damage and being unable to reflect without complete defensiveness. I would push the issue because I needed to 1. learn from it and 2 resolve the hard feelings associated with it. Rarely was this satisfactorily accomplished. She cannot seem to reflect on her own behavior and so we have a constant stress level in our relationship. And many, many issues just keep causing the same conflict. We have learned over time with this "GroundHog Day" that she has a raging case of ADHD. Getting her to own this diagnosis, take her medication, and try to do something other than starting and escalating conflict when the cycle happens has met with failure time and again. We have taken the course, she has done coaching and when my wife is focused in on her sx things will be better for a time. But eventually she stops the medicine and things slide right back. This has happened numerous times. She seems to try so hard which had inspired me to stick it out with her over the years. But in March we were getting over another argument and I made her promise she would take the lead on practicing therapeutic communication exercises. She didn't do so of course (makes her feel silly)so I did. After about 3 days of taking this lead I walked in to ask if if she was ready. She rolled her eyes and in that moment everything changed for me. A light went on and I realized this will never get better between us. Her trying knows many bounds and things have been cold since. If July she finally confronted me and I told her divorce was likely the best option. I don't feel ithere is hope of improvement and that I wouldn't trust her even if there were. Why should I keep subjecting myself to this mountain of dysfunctional behaviors? What is our duty to ourselves? When is enough enough?