MakingMeHappy - go easy on yourself. It sounds like you were in survival mode, and you did what you felt you needed to do to protect yourself and your child. Think of a mama bear - when someone threatens the safety of her cub, there's no, "Excuse me, but it would be preferable if you move along," there are swats and roars!
It's great that you recognize that you can improve your communication and work towards positivity...but do cut yourself some slack. (And I think we can all look back at interactions with our A's and in hindsight find "better" ways to communicate or deal, so you're not alone.) You're in a better, healthier place now, and I'm really glad to hear it!!