Hi, I have been through an inordinate number of losses, loved ones and pets, and several of those losses to cancer. Loss is very hard and grief is hell. Allow yourself to go through it, not suppress it, but to feel your sense of loss. It's a lot of pain. I will tell you that in my experience, seeking out spiritual guidance is helpful. That guidance can be a meditation practice, for example. It's helpful because it inspires you toward self-growth and gives meaning to the loss.

One thing I'll add- there is, of course, a large amount of anticipatory grief when someone(s) is dying. That said, they're not dead yet. As long as they're alive, enjoy the hours.

Best to you.