Feel terrible

It could have been much much worse, and I thank God it wasn't. I was across the room and my son was playing near our dog (9 y/o lab). He got a little hyper and jumped on her. She snapped at him and nicked his forehead. Obviously she is an animal and could have really hurt him if that's what she meant to do. But ultimately it was my fault. I always say you can't trust a dog 100% and here I am. My husband gave me a disgusted look that this happened on my watch. The same look he gave me 3 weeks ago when our son fell and busted his lip. It brought up feelings of me being inferior to him as a parent. I have never felt that I fully deserved him as a husband and now our son has been injured twice on my watch. I come from a lot of mental health family problems and not good parental examples. So my confidence as a mom is not so great. My husband family is "perfect" so I think he probably is naturally a better parent. I just feel like I am failing my son and not good enough to be his mother.