I lost both my parents in my late teens early twenties.
My mother died first, she was young, she had successfully fought cancer for 7 years.
I was very calm, people cried around me, my one brothers wife was nearly hysterical at times, I handled funeral arrangements and my dad was just kind of floating absently through everything, distant at times, crying at times.
I gave my mothers eulogy, she was a great person, nearly a thousand people came her funeral. She worked heavily with special needs children and was giving, amazing and genuine.
I had nightmares almost every night for a year.
They were awful.
I was never particularly emotional or weepy around others, I don't think I wept at all during that year of nightmares, I did the things that needed to be done and only wept occasionally afterwards.
People process grief in different ways, I had moments where I reflected similarly to you about my lack of emotion...
The more years went by the more I missed her, situations or events would arise and I would almost physically crave her presence and opinions... her person.
It was all there the whole time, losing her was devastating in spiritual, emotional and practical ways for myself and my family, people just respond differently to these kinds of things, there is no one right way and people who demand a certain types of expression of grief... well I've found they often, strangely, lack empathy.
For some people emotions run very deep but don't obviously surface (even internally.)
You will feel grief as it comes, no need to suppress, drum up or prematurely meta cognate about it. The waves will come to shore and you should let them when they do.