Here's an incredibly effective one-minute exercise I learned from Sam Harris, one of my favorite writers and thinkers. I highly recommend doing it today, maybe even right now.
As the day fades today, see if you can identify your lowest, worst moment of the day. When you were at your worst self; maybe you were agitated or worried, or angry at someone or something.
As you ponder this unpleasant moment, try to bring to mind a single thing you're grateful for; your favorite person, the fact that you're relatively free of pain, or just feel ok about where you've landed in life.
Life can always be worse than it is right now. Think about all the people in the world who would consider their prayers answered if they could trade places with you at that worst moment. There are literally billions of them.
Imagine what it would be like to lose everything -- maybe your house burns in a fire, maybe you lose your family and everyone who means something to you. Then, imagine your situation could be magically restored to the moment you're in right now, and how you would feel post restoration!
Go back to your lowest moment of the day, and try to instantly transform your experience in this way. You can almost always do this, but the hard part is remembering to do it ("the most important thing, is remembering the most important thing").
You have your health, however imperfect. Maybe you have a single cherished friend or relationship. Maybe you have your favorite ways of spending time, and have the freedom to pursue them. You've almost certainly spent today without encountering some terrifying form of chaos, in contrast with much of the world.
So take a long slow breath, and feel how lucky you actually are. You're still in the game; you get another day to live on this beautiful Earth, whatever its flaws. Just take a brief moment to revel in that. It feels so good to do this!