I never seem to know what to say to people when they are grieving. I have found that anger is a norm in the grieving process. I can understand certainly where you might have more anger then what I have experienced. I am sure you feel like your brother-n-law cheated you and your family out of many more
family get together s and Holidays. He promised you he wouldn't try such a thing again and then broke his promise. I would be angry too.
I can understand why you would be angry at your sister-n-law and son. They should have been more understanding with him and kinder. I can not imagine driving a suicidal person to get a gun. Especially someone I loved. I might drive them to a therapist but certainly not to a gun store.
I think you have every right to be angry. Have you ever heard The EAGLE'S song , There's A Hole In The World Tonight ? There is a line in the song that says.Anger is just love disappointed. I have found that is usually the truth . Your anger is just love disappointed. I think that fits all of us here at Webhealing.com
Of course you are hurt. You have lost part of your family someone you love.
Keep praying, God hears you and He will answer you. My brother use to tell me that God is never early, He is never late, but He is always right on time.
Sometimes our faith falters when we lose someone because we don't understand why it happened. I guess our grief and confusion makes us weak. Those are the times when we just have to say, God you said when I was weak you would be strong. Well God I am weak and I am reminding you of your promise to me. I can't get through this without your strength. You said to lean not tour own understanding, and God I don't understand. so I am going to leave all this in your hands. I am going to trust you to make me better and not bitter. Restore peace in my soul.
I personally pray that a lot and it does help.