At age 71, this is the only time I have felt grief for anyone.

Grief: an unknown problem.

There is much background for you, dear reader, to know about me before I can sensibly explain my inexperience and immaturity with grief. So...background...
...My childhood was haunted and full of anger and hatred at my adoptive "parents."

*NB: From this point on, I will make reference to my adopters and their extended families with the pompous adjective "fictive." I never bonded with those people; they were fictional in my mind. Hence: "fictive" sister, cousin, father, etc. The fictives never did get near to me. I already had my own birth name; I already had my own personality. My adopters took away my entire given name! A DOG knows his own name, for Christ's sake!!
I'm glad to be the last one of that entire fictive lot, and particularly pleased at the fact I carry zero percent of their DNA. I got several nice inheritances. Bag money! A nice little trick.

So now...to "grief":

Here I am today at age 71, and I have lost my big brother (74) to Alzheimer's. The disease took him away in two quick years. I am emotionally helpless.

The only human being I bonded with in early life was Pete. He was quietly intelligent, thoughtful and very talented with his hands. He showed me how to fix things and make new things. Pete and I often talked about being adopted; We each had our own theory about it. Adoption was a satisfactory situation for him as he was taken away at age 3 days. I was abducted by my adopters at age 3 1/2. I lived in foster homes until then. I was a tough nut to crack.

Losing Pete has nearly dropped me. I already have chronic pain; now my suffering is doubled.
I have only ever felt joy and vengeance at the death of every member of the fictives.

The realization hit me with a punch that I don't know the language, politesse or meaning in life of grief.
I am obsessed with my mixed-up state of mind. I cry. I feel depressed. I am angry at life - 'Why HIM and not ME? I would gladly have switched places. Does a person in grief talk about it with other people? In detail? Or is it just kept quiet? As a man, am I supposed to not openly grieve to display my inner strength?
I've been having suicidal thoughts. But I'm a Canadian and we don't generally have access to handguns in this country!

What do I do about my turmoil of bad feelings?