One of the best tips for writing descriptions of pain is actually a snippet I remember from a story where a character is given a host of colored pencils and asked to draw an egg.
The character says that there’s no white pencil. But you don’t need a white pencil to draw a white egg. We already know the egg is white. What we need to draw is the luminance of the yellow lamp and the reflection of the blue cloth and the shadows and the shading.
We know a broken bone hurts. We know a knife wound hurts. We know grief hurts. Show us what else it does.
You don’t need to describe the character in pain. You need to describe how the pain affects the character - how they’re unable to move, how they’re sweating, how they’re cold, how their muscles ache and their fingers tremble and their eyes prickle.
Draw around the egg. Write around the pain. And we will all be able to see the finished product.