Your projections into the future are overlooking a lot of other possibilities. What about the one where you remarry a great guy who makes an excellent stepfather? Or the one where you stay in the marriage for the sake of your child and she grows up with an emotionally distant father who makes her feel she's never good enough and an unhealthy marriage as her main role model?
Some advice for the face to face discussion with your H - write up an index card with advice to yourself and your main points you want to make. Put it in your pocket and excuse yourself to the restroom to reread it if you feel things are getting off track.
