I noticed last fall that her communication with me- both in style and in frequency- reminded me of how she communicated with her ex-husband and I thought to myself "holy sh*t, she's treating me like her ex now. What have I done?"
Maybe a form of displacement where you became the safer outlet for her unresolved issues. Kind of like having a bad day at work with others, not being able to deal with it there and people go home and take the stress out on family members.
What id like to point out is that it is not for me to judge and say that it doesn't sound like much fun what you went through, being how it comes across an emotional swill bucket for her issues where you could have done other things, I went through part the same, it made me ask "you are wasting quality time we could be having now" (asked myself) not her.
But if we state that we enjoy that sort of thing, taking on that role - it shows how the relationship worked, and complemented each side. It makes it difficult to complain about or consider being "used". It is hardly being used if it was acceptable or even enjoyable to want to be there in that role.
Healing and moving on for me has been accepting that I actually wanted more than I got, that I put up with stuff I shouldn't have just to appease. A sort of go along to get along. It kept the relationship going, but it wasn't really me, and it helped to experience it to maybe understand more about myself and what I expect in future.
I asked "now", with wondering if you ever truly believed her story from the start or if it is just being questioned now that it got to this point of being difficult to handle. Maybe parts of her story in those hours might have some point sounded too one-sided, or embellished, exaggerated even, if so - did you ever call her out, or ask for more specific details? Or did you just listen and accept the one sided story? If so, ask maybe why you did and was this a product of getting carried away in emotions and maybe neglecting the rational logical side which is less fuzzy warm inducing, more cold, business like.