Therapy makes me angry???

Im doing DBT and I was doing talking therapy which i had to stop, the more I discovered about myself the more angry i became at my family and the people around me, even now while im doing DBT afterwards for a good few days im so angry at specifically my parents, is it because they were meant to "protect" me as a child and didnt or what i dont know but i also dont know if this is normal when you start therapy, im worried the more i do the more im going to resent my family what do i do?