you didnt do anything wrong. self blame wont help a thing!
it is hard with blended families for sure, as both sides cant help but be more defensive of their own kiddos.
you have a choice though on how you respond to things. I would very quiet and calm and tell your husband that you wish things could be better and are praying for solutions.
read this book if you havent already-free to borrow at the library:
boundaries by townsend and cloud.
really help me not let others hurt or use me up so much!