How do you manage to stay grateful in difficult moments

I try to think about the little things that were positive or made me happy. For example I can be grateful for that delicious breakfast that I ate, I can be grateful for the fresh air, for the walk in the park. I also try to see something good in something bad. For example I can be grateful and proud of myself that I managed to survive through a difficult day, even if I didn't act as I wanted. I try to see difficult times as a lesson, as my opportunity to grow.
All of it is not always doable. If so, I can always be grateful for that I'm trying to be grateful, because that means I'm trying to take care of myself, to be better and healthier. Hope it helps. Good luck!

I make myself remember the things that I have and that make a difference in my life. Gratitude could be towards small things, it doesn't have to be something huge, that way things will seem smoother.