Closure conversation that left me with self-doubt. Help needed

I had what I hoped was a closure conversation with my FA ex last night after a year post-discard. And I'm left with tons of self-doubt. I told her I didn't feel she communicated that our relationship ended and that I felt blindsided when she told me she started seeing someone else. I asked why she didn't talk to me or give us an opportunity to repair after a relationship that lasted three years. She said I was blind to the situation and wasn't willing to accept reality that it was over and that, unless it's marriage, there's no promise that the person needs to work out anything with you and they can decide on their own and leave when they feel they don't want to be with you anymore.

I don't know what to make of this. It's not how I see relationships but maybe I was blind as she said or have unreasonable expectation of relationships or people communicating or working things out. When I asked why she talked to me about our future together if she didn't want to follow through, she said she was testing options and imaginations. It's very confusing.