"and I guess I'm starting to feel the weight of maturity on my shoulders..." Stunningly revealing statement....and so true. You are about to enter an era of your life that many of the invincible on this site can't comprehend: Maturity, responsibility, the importance of being an elder, etc.
I have no grandparents, and recently I attended the funeral of a close cousin, who's last grandparent had just died. He said to me, "You know....the next one <funeral> is gonna be a bitch....because the next one is going to be close..."
I'm married with 2 kids, one a teenager, the other a teenager next year. And yet, I still look to my father for advice, and I respect him (again...a notion that a lot of the younger members of this site don't quite grasp....the idea that your elders DO know more than you!!). My cousin was lamenting the idea that I am now the third oldest of the close cousins....that his parents were the eldest....that the next funeral we attended together was going to be somebody horribly close to me on an emotional level.
That is a cold, hard smack in the face. And yet, it is simply reality. It is the same thing that everyone must go through. But it is a chance to step up, to become a family leader, to take the role of a family elder and actually influence a younger generation.
Funerals suck. Death sucks....and yet, as a Christian, i don't mind them nearly as much as the lost, because I have faith that i will see a lost one again. You may mock that comfort as absurd....but you can't take that comfort away from me. That is the beauty of faith!
Anyway....tough times. I feel for you, bro....and yet....don't view it as bad....just view it as change, as opportunity. Reflect strongly upon this moment and don't let it pass without becoming a better man to all around you.