Pants vs a whole bunch of things

I wonder if someday I'll come up with titles that don't involve me vs'ing things.
We lost a member of our family after a 3 year battle with cancer that saw him through diagnosis, remission, and back to diagnosis.
Cancer is like that. It comes. It goes. It takes from us those things we wish we could hold onto forever. Forces a sense of morality.
I've had enough death. I reckon anyways. Enough grief and processing and trying not to grieve and process.
The hardest part, I've found, is the finality of it. The concept of not being able to take it back. To go back. To change an outcome.
I mourned the death of friendships. Ones lost to stupid things like lying and emotions and the inability to retract from pride. I've mourned you and her and them about ten thousand times. But I've always known that it was never final. I've known that she'd text me trivial conversation. Test the waters. That you'd email me. That you'd apologize and so would I. And that they would question my sanity, my stance, trying to gauge my reactions based on some form of words on a screen.
I've mourned lost relationships. Ones I could not make work. I could not forgive. I could not overlook blazing trust issues and immature reactions to grown up feelings.
I've mourned the loss of who I used to be. A person I sometimes miss. A person I sometimes wish I could go back to.
I've mourned all that. Loss and love and everything in between.
But losing my best friend. Holding the 8 ounces of ashes she was reduced to. That finality. That end. That total end. That I have trouble with.
My cousin who passed away. We were not very close. I have few memories of him aside from beards and a vague recollection of boisterous laughter. But the finality, the knowledge and not just the notion that I will never speak to him again is a struggle I'm not quiet sure what to do with.
Is there ever any healthy way to approach grief?
I don't suppose there is, because if there were, the book would be a beat seller.