You are doing extremely well, none of this is easy; we are all human, and of course, there are situations where we can be flexible.
However, keep in mind, that tough love mixed with the insight to see what is really happening in a situation, gives everyone in a relationship what is needed to not be taken by any addiction. I like to see the addiction as a separate identity, bullying the addict to believe lies, and of course it tries to bully friends and family imhumanly. Standing firm is like being an advocate for the person, and of course yourself and child. It is never wrong to show compassion, but not enable. We all know the worst type of enablement is monetary, that is a line, in my opinion, does more harm, as the addiction has gotten what it wanted.
Living life the fullest with your daughter, sharing precious moments together is what matters the most. The next time your ex doesn’t call or do as he says, let it roll down your shoulders and off of you; don’t let it bring you or your daughter down. Show that you are not interested in games.