Thanks for these thoughts, MTN. Here is some of what I have learned:
Be patient with yourself. Grief takes time and takes its own time. Since you cannot know how long that will be, do not be hard on yourself for letting what needs to happen for you run its course. It is not a waste of time at all to explore this territory, much as you might prefer to be done with it and have it all behind you. You will stop crying or stop mourning when you are done crying or mourning.
Now I say this b/c it has taken me a rather long time to get it all done. The divorce for me will be final almost exactly 3 years after my h moved out (which turns out to be a year for every decade of marriage). Grief has not left my heart though I get along day to day and mostly quite happily. And I say this b/c I have heard others say that they were sorry they wasted so much time obsessing over their sitch. For me, it is just the process.
Count your blessings, be they your children, your friends, your parents, the roof over your head, your accomplishments at keeping your life together or whatever.
Consider keeping a journal. This has been one of the most useful things for me, and something that is not just what I have written here over time. I have found that I can work out problems as I write down my thoughts. It has been very helpful to look back and see where I have been.
Challenge yourself. That is when you realize that you still remember how to eat and breathe and can look around to think about what is next.