So truly sorry!
I lost my mom to suicide when I was 19. She did leave a note but didn't finish the one to me so I never got to hear her last feelings for me. That was really hard to swallow.
Can you tell us more about your brother? How did he do socially? Was he well liked or on the sidelines?
You're doing the best thing by expressing your emotions. Cry when it's time to cry, be angry when it's time for anger. Let everything out when it's in you to do so. That is self-healing.
And take life one day at a time.....