Hi empathic
I am honest I have mixed feelings about talking someone into T. What I mean is more like a suggestion. At the end she has to make it on her own.
Same for you.
I can relate very much with the relief about being alone some days. I had similar thoughts the last year in my now finished marriage. I went to a T in my marriage to find out how I can deal better with my H and it turned to the topic: Do I want to be in this relationship or not?
True, I probably can't make her go to T. What I can (and probably) will do is start T myself and suggest she do the same, to prepare for CC later on.
I don't think she's comfortable in making it on her own, she never really has been. I think she's used relationships as a way to not have to deal with her own problems (me speculating). She doesn't like to be alone. She too might be mourning what we once had, but she cannot see her part in it, the effect her temper and comments have had on me.
And she's changed a lot over the years. Before, after losing her temper she'd come out of it and be extra nice for a while. Nowadays she never does that. It's like she thinks she's right about everything now, and never needs to apologize. The little empathy she had back then is gone.
A probable outcome of my T can be as you say, that I prepare to end the relationship. But it will be hard, my wife has serious issues with abandonment and I can't see her making it easy on any of us.