Tattered Heart,
I wish I knew your story better. For now I'll share some general truths that have stood the test of time.
The goal of leaving is not for divorce, but as a wakeup call for him to get help.
Leaving a relationship to "communicate something" other than "I'm leaving the relationship" usually brings confusion and disappointment to both people in the relationship.
I would encourage you to create a plan that is consistent with a message you want to send.
Can you understand that "I'm leaving you so you will wake up and we can get back together" is confusing to some?
I love metrics... .I fancy myself a "metric based decision maker".
What can you add to the metric that describes what you will be doing in the interim to "do your part" for the r/s. (this is where I wish I knew your story better... .I understand you very well may have been doing "your part" for a while or perhaps there are areas where you contribute... I just don't know)
Big picture: Leaving the future of the r/s in the hands of a disordered person to "make the metric" or not... .is usually not a good recipe for the r/s to succeed.
FF