I’m terribly sorry for the death of your friend. Don’t be hard on yourself if you are having trouble “getting over it.” It can take 3 to 5 years to fully integrate an important death. That doesn’t mean you’ll be sad and mad all the time. It just means that every now and then you’ll really miss your friend and you’ll feel the grief all over again for maybe a few minutes or hours. This goes on intermittently until it becomes more like a dull ache instead of a sharp pain. When someone important to us dies, it leaves a hole in our lives that we may eventually accept but we don’t have to like. Just know that your feelings are normal.
As for your grandfather: I don’t think he dislikes you. The two of you are dealing (not too well) with a generational difference. When your grandfather was young, it was considered just plain rude to tune people out or to continue with an activity when someone is talking to you. He feels insulted that you prefer your music to talking to the family. From your point of view, wearing headphones only makes you like everyone else your age so what’s the problem? It’s not a matter of right or wrong. It’s a matter of different expectations for courtesy and different ideas about the meaning of a behavior.
My advice? Apologize to your grandfather (that’s right, apologize) — not because you are “wrong” but because you unintentionally offended him. Explain to him that listening to your music is helping you cope with your friend’s death and with other things that bother you. See if you can make an agreement of some parts of the day when you take them off and can focus on the family. Ask your grandfather if he has any advice for helping you deal with grief. Grandfathers are often wise. He will feel included in your life.
As for the world turning against you: Your nerves are on edge right now. You’ve suffered an important loss. You have already lost your parents in that you don’t live with them. You may be frightened about the possibility of losing your grandfather as well. It’s understandable that getting angry and stressed out feels easier than letting yourself feel your fears. But showing how vulnerable you feel will bring others closer to you. Being angry or defensive pushes them away. Please think about it.
I wish you well.