Your heart will catch up with your mind......just let your mind be in control for a bit more time! You get it and know what is best for you and your daughter....keep moving forward and it will get easier.
Addiction aside the kind of man who needs to jump right into another relationship is to be avoided! You can't trust or rely on them in any respect. My experience with this was with a Narcissists. He had no identity unless he had a woman to use as a mirror - that quickly turned abusive since nobody can be a mirror for long and then they start to hate you! Anyway after 8+ yrs.....separated from my X for 3 weeks.....in that time he signed up for a spiritual retreat....went for a week.....and met his "soul mate". Poor thing.....not sure how long she went for that ride. When I found out I went 100% No Contact......
Hang in there and continue to do what you know is the best for you!!