It's easy to get bogged down in the fertilizer of Life. You're not as young as you used to be, after all. The kids can run you ragged, and then there's the adult child who caused all this, who still might be involved in the situation. Money's tight these days for everybody, and getting kids what they need is hard enough, let alone getting kids what they want.
It sounds trite, but count your blessings. Count them on your fingers in a quiet room, or list them on a sheet of paper, or type them out. But take time to think about what's good in your life, and in your world. You'll be a lot happier if you do; at the very least, you'll see there's a reason or two to hang in there.