I can't speak specifically toward your situation, because I don't know you, but I think...

We do all grieve differently. Sometimes, our body knows when we can't handle it yet. I know you feel numb. Maybe being numb is what YOU need right now. Your friend that just passed... was your friend. I don't think that they would mind, because they knew and loved you in this life as how you ARE.

Grief isn't measured in any certain way. You care for them enough to be upset that you aren't upset. That is something. You will deal and feel in your own time. Don't set your watch to anyone else's schedule. Try not to judge yourself too harshly. You are already in pain. It is easier said than done, but be patient and gentle with youself. You are feeling what you need to be right now.

If you are up to it, I would suggest doing something that honors your friend, you and the relationship you shared. Maybe you got together for coffee and a chat, or to watch a certain TV show, etc.

(It is my personal belief that the people we care about can still hear us in the next life.)

Maybe just making that cup of coffee/tea for yourself and your friend, or just lighting a candle/insence... think of them, and tell them exactly what you feel in your heart. It doesn't have to be terribly meaningful. Don't think of it as a good-bye. Just have a conversation. Just like you typed out here. You can always mourn him/her in a different way when you are up to it.