I am very sorry for your loss. I lost my father suddenly when I was 19 years old, so I know how such a thing feels. It s not easy to lose someone. Even if you can see it coming. My father lost his mother at 12...seems to parallel your family a bit.
The advise to not stuff your emotions is very good. It's important to feel them, so the stuffing of them doesn't become a platform for bad habits, like drinking or drugging, etc. I thought, for years, that I had dealt with what happened, but years later, I realized that I had not, and it caused me all sorts of grief. I don't know if that's avoidable, frankly, because things take their own time, but it's worth finding someone you can trust, who will allow you to say and feel whatever you need to. Doesn't have to be a therapist. A friend or relative will do.
Good luck to you, Alehand.