I'm mad at my brother

This is going to make me sound like the most selfish person in the world. And I hate that I feel this way. I feel so guilty, but I can't help it. My little brother has been for almost 13 months. I thought that would be enough time to stop feeling this way, but I'm still so hurt by the situation. He died 6 months ago because he choice someone else's life over his own. A girl that he didn't know had been tricked by one of her girlfriend's. I dont really remember exactly what happened, but her friend had some plan to get her raped by her boyfriend. My brother worked down town and his car was being fixed so he had to walk. He was 17.5. I'm guessing he heard commotion going on between these two tax buildings and went to investigate. I'm only able to tell this from what the girl said so idk everything that happened, but she said my brother pulled the guy off of her and she ran and my brother and the guy started fighting. She called 911 and heard a gun shot. This man murdered my brother. Both her friend and the rapist were arrested and ny brother died in the hospital... I'm proud of him for saving her... But mad at him for choosing someone else's life over his. My brother wasn't supposed to die at 17... He was supposed to turn 18, go to college, get married. He spent his whole life putting others first. When he was really young if you asked for his cookie he will give you his cookie. He's a good person, or was a good person. I hate that I'm mad at him. He deserved to live! I hate that good people don't always get happy endings... I hope that as more time goes by I'll stop feeling like this... I wish he got to live out his dreams and get his happy ended. Not just be a body in the ground...