Two kinds of activity, and you need both
Researchers who watched what bereaved people actually do, rather than what they were supposed to do, found two different kinds of activity.
One is facing the loss. Remembering, crying, longing, looking at photographs, going through their things, making dua for them, talking about them, missing them in a way that hurts.
The other is dealing with the changed world. New tasks. Jobs they used to do that are now yours. Going back to work. Seeing people. Being distracted. Ordinary Tuesdays. Things that make you laugh.
The second one is not a betrayal and it is not avoidance. It is half of what grieving actually consists of, and nobody gives you permission for it, so you have to be told.