The dynamics of M are complicated, even if you were some of those things it doesn't make the breakdown of M entirely your fault or his. When we act/react a certain way to our spouses it causes them to then react. That reaction gets another reaction from us and it spirals out of control, back and forth. This may happen over years and years with neither spouse realizing its happening. No matter what you were, or what he was, both individuals were responsible for the M and how it ended. The more important part is that your looking inside yourself and realizing how you can change. Some people blame the other and never accept their role, which is a major issue and will only cause their future relationships problems.
My W's divorce papers are shoved in the back seat of our car scattered around, a couple of the papers are even on the floor crumpled up. She has no motivation now to file them. Shes justified her interactions with OM due to us being done. The paperwork is just a technicality right now that she cares not to deal with. For the time being anyway. I still don't believe she could mentally deal with the process right now anyway. She couldn't even handle reading over a simple document explaining after school child care for our D.
Accept what is, let go of what was, and have faith in what will be