For my father, having just lost his wife of 59 years, grief is in the details. Every action, every breath of every day is filled with the loss, from the moment he wakes until he returns to sleep. Every chore he has to take on, every lonely lunch without his cribbage partner, every unshared TV show underlines the devastation he is forced to live with.
I have lost two life partners, but no one with whom I have spent so many years. When your beloved spouse dies it's as if the entire fabric of life has been shredded. To say you feel "torn apart" is an apt metaphor. And, there really is no one who can possibly share that grief you have to bear. There are others who may understand some of what you're going through, because they've been there, too. But, ultimately, all grief is excruciatingly lonely. No one else had the same relationship with the deceased as you did.