So sorry for your loss. I cannot add much to the responses you have. My first thought is that you are in shock. What AnnieBrooke said may well be another factor.
When my son died suddenly, I had unbelievable feelings of pain/felt a wind pass thru' me when I believe his spirit departed his body. My daughter and I were in my apt, and really didn't know for sure that it was Brooks who had died. The event was on all news channels...but it was three hours of waiting and praying before we had word.
Two of my sons were with their father when he went on a rampage: he shot eldest three times until he fell..no longer able to shield his younger brother. My ex then killed my younger son. From what I heard, he felt he had killed them both. No remorse. No attempt to run. His trial was this month: prison for the rest of his life. Justice is done.
I don't know what killed your son.....just that a sudden death is a huge shock to the body.
And ..it is true ..there is no one way to grieve. In my family ..each is going thru' it differently. At least now, we can talk about fulfilling my dead son's dreams for the property where he was killed.
We will soon have a beautiful park to visit for picnics. My youngest son's method for grieving is to spend every spare moment clearing and cleaning and building . The acreage was jointly owned by two younger sons.
Take care of yourself. Post again whenever you feel like it. This is a good place with lots of caring people to support you if you need it.
I would agree with the "in shock" idea, sometimes the shock is so severe that you simply go into survival in order to maintain living, and only later, when things feel safer, can the grief come out.
The other possibility (and I know a couple who were married for a long time for whom this happened) is that you had a very complete relationship, and didn't have a lot of unfinished business that tugs at you now, so maybe you are content that you will see each other again and things were at peace between you.
Or a combination of the two.
I am sorry for your loss. Please remember, there is no 'one way' to grieve, everyone has her (or his) own way.
Maybe you are grieving and just do not realize it as a form of grief. Or perhaps because it was sudden you are still in shock from it all and need to get past that first. When my mom died it was sudden and unexpected and I think it took a long time to get over the shock of it and then I think the grief really set in.