My father took his life and I didn't grieve about it

I was raised in a loving and supportive family, and my dad contributed so much to my happy childhood (playing games, reading so many awesome books, teaching me lots of useful skills and sharing knowledge in physics, engineering, technology, etc.). As time went by, unfortunately, my dad became a deeply troubled person as I was growing up. His health deteriorated with some hereditary chronic diseases, and he got caught in the huge crisis in his industry and lost his job as well as some of his friendships, which caused his mental health to spiral down to depression, a huge amount of anger and dismay about everything in life, including his own wife. He was slowly becoming less and less controllable and very easily irritated, and didn't hold off from episodes of threats or direct physical violence to members of my family (excluding me, though).

At his late 40s, he began contemplating ending his life and taking my mom and me with him and even discussed these ideas with his only friend that he had by this time, but in reality, he ended up committing suicide a week after his 50th birthday by an insulin overdose (he had had severe diabetes for all these years). The events that took place after his passing trouble me to this day, eight years later - my mom had a breakthrough at her job with a huge bump to our income from near poverty to stable middle-class levels; I suddenly began building relationships with peers at school after some years of conflicts and isolation; my grandmother's health stabilized and she's doing much better these days than in the years before my father's death. The point is that I, a 14-year-old shy and genuinely well-raised kid, didn't shed a single tear at my father's funeral, didn't mourn or grieve his passing and even felt upbeat and positive about life just a few weeks later.

Nowadays, though, with my dad's contradictory legacy continuing to unfold, I feel like I missed the moment to pay deserved respect to him and also think more about what his life, downfall and death meant to me and all of us, while also not learning the lesson properly about his character flaws. I really wish I had my time of grief when it mattered the most, because today I certainly know this event changed my life forever and has an impact on my whole being in a very complicated and upsetting way...