I think an apology to the child is essential and can indeed be healing. Maybe more than one apology over time will be necessary, especially if this is a repeated pattern. I think behavioral strategies for avoiding blowing up around your kids can be helpful and would be a good topic for talking to ftt about. Most therapists would have very practical ideas for how to deal with this. Meanwhile, in therapy, you can continue to do the difficult work, but outside of therapy, you can manage your behavior so that others aren't impacted by it. I think removing yourself from the situation is one approach, another is to learn ways to express anger less destructively (easier said than done, I know). I remember once my T said (in regard to expressing anger)--expressing anger is OK, but rage is not. I think he meant that rage can be really damaging to the other person, that rage is out of control. Anger need not be damaging or out of control.