I am really sorry to hear about your son, Mando.
A big hug for you and your family.
When my ex boy-friend's younger brother (12) was killed by a truck he actually came to say good-bye to me. OSIT. I could see him bathing in some light, smiling broadly. It was totally unexpected.
When I lost my second mother I also felt her presence somehow.
I know from a friend who lost her husband the same thing happened. He is still around somehow.
I have also felt his presence. Not at first, as I was furious with him, but when the anger subsided and I understood better what his role had been I could see and feel him.
Not sure whether this helps.