Self help books on grieving loss of a loved one (tw discussion of murder)

Hello everyone. I lost my best friend last week. He was shot and killed by someone I considered close as well. I’ve lost two people essentially. I don’t want to get into details. But I’m lost and heartbroken. I don’t know what to do. I want to learn to live with this pain but it feels impossible. Can anyone suggest a book that involves dealing with grief after a death? Bonus points if it’s more specific about losing a loved one through violence. I’m trying to keep this short and sweet, so thank you for taking the time to suggest something

by plastictree343