My wife had a similar conversation with me after 23 years of marriage.

My daughter was already off in college and I got the feeling she had already set a plan in motion.

She wanted end it , yet she wanted it to be my fault that the marriage failed. She blamed me for numerous issues, all which would be considered minor or petty. She accused me of having affairs.

Finally we had a conversation that set the wheels in motion to end the relationship.
She still wanted to find a way to keep me hanging in case the split did not work in her favor. Keep me pining for her while she went off and dated someone else.

Well I did love her but screw that. I found someone who actually did love me. A much younger woman that was kind, beautiful and giving.

So her plan did backfire. In the end the reality was that we were not right for each other. So now I am married and truly happy while my ex ran through a series of relationships and is still not married.