What are the worst things that could happen to you? Write them down. Have any of them happened? Chances are none of them have. So shouldn’t you be on top of the world?
Imagine if they did happen, and somehow it all got reversed. Wouldn’t you be the most thankful person in the world?
Put yourself there visually. Imagine the very worst things have come true. Feel it, as though it has happened to you. Feel what it would be like.
Then come back to the present. Come back and be thankful. Come back and live your life differently. With gratitude. Thankful for everything you take for granted.