I just want to add...
For a LONG TIME, I tried to write the story my marraiges' demise in my own head before I took action. For some reason, I felt like I had to PROVE to myself, my exah, and the world that the failure of our relationship was HIS fault...and not mine. Subconsciously, I think I wanted to be able to say 'see...see how hard I tried...see how much of myself I gave up and compromised?...yep...it's all HIS fault...".
The thing is...it doesn't matter WHY the relationship is failing.
When it becomes harmful to you and your child, you don't need his permission or anyone's permission (including a marriage counselor) to walk away. I wish I had realized this sooner.