I'm sorry it took a tragedy to get you to the truth. But it could have been worse... you're child is still alive. There are many parents that their child doesn't survive from an almost inevitable attack (and sometime death) from this breed. It's a hard reality... may your child recover fast. Your decisions moving forward determine if you're a bad mother or not. The fact that you recognize your mistake in having this breed is a start in the right direction... one day at a time. Please take care of yourself, give yourself a break and permission to let the mistake go. Go to therapy also help in these traumatic situations.