I know how hard a loss is. With it being so close to the Holidays it is more than likely to have a double impact. I am very sorry to hear about this. I'll keep your family in heart and in prayers.
I certainly extend my thoughts and prayers. Having faced the suicide of a friend, I cannot imagine the magnitude of the suicide of one's own child. My condolences to your sister, brother-in-law and nephew.
Anger is quite reasonable. I had a friend comit suicide, and found out a lot of things I would have never thought about him when I did, and many of them made me angry.
Of course, I overreacted when another friend disapeared a few days later, but better safe than sorry in that case, since they were both friends as well.