Fiance and I have a huge problem? But is is about my brother?

My brother cut his back open cuz I pushed him into the fireplace and ya. But My fiance is mad at me cuz I wont call 911. I can't my mom driving home and said to wait. I'm trying to stay calm and keep my sister calm but with her yelling at me I cant and keep getting mad! And my brother is 15 and like bleeding everywhere!