Simple:
* He felt despairing after the news of his friend's death.
* The refugees looked despairing as they crossed the border.
With Description:
* Her voice was filled with despairing hopelessness as she spoke of her lost dreams.
* He stared at the empty street, his face etched with despairing loneliness.
Figurative:
* The city was a despairing landscape of crumbling buildings and forgotten dreams.
* The silence after the storm was despairing in its emptiness.
In a Dialogue:
* "Don't give up," she said, her voice trying to sound hopeful, "don't let yourself become despairing."
Remember, "despairing" is an adjective, so it needs to modify a noun. It can also be used as a verb, meaning to lose hope.
Let me know if you want more examples or have other questions!