Hey, so sorry for your loss. My heart goes out to you and your family.
The loss of a parent is unimaginable, but your brother may be grieving in his own way. Some people just react differently to trauma/grief than others. Who knows, maybe in private he's melting down. He might just be good at keeping it inside. If it's worst-come-to-worst, then I'd say maybe he has an issue with empathy and feeling for others, but perhaps it's just him masking everything. Trying to be strong maybe.
Anyways, back to you...
You don't need to have a good relationship with whomever to have the feelings you are having. It's only natural you feel as you do. After all, it was your father who passed. From what you've typed in your responses it seems to be more than just your father this year...and to that I am very sorry as well. Hang in there. Alcohol and other things of that sort are not good coping mechanisms for grief or anything for that matter. It will only make the feelings worse ultimately. You have to face them and deal with them in your own time. I'm not saying it's going to be easy, but it's not something you have to do alone. I hope you can reach out to someone in real life, or even on here to help you cope with your losses. You are not alone.
We don't exist to die, and watch others die...but the reason we exist is very vague to me as well. I don't think it's that cruel though. Something I saw someone write is that "God (or Fate) has a plan for us", and I honestly like to believe that. It's hard to see sometimes, but I like to think it's there.
Take care, alright? Feel free to make another post or message someone if you need to talk. My inbox is open