'tears rolling down my cheeks' is correct. Tears don't roll down your eyes!

Tears technically and scientifically "run" or in the past "ran" down your cheeks or face, because they are liquid, liquid runs or flows. Things that are a globe in shape like a ball, or a barrel, or wheels "roll" or a ball bearing inside a bearing rolls. "tears running or rolling" as an expression means something that made you cry a lot, often used to mean with laughter. Idioms are not technical or scientific. "tears run down your cheeks in the idiom", but it often gets misquoted to include my eyes, my face.

It's a sentence fragment. You could say e.g. Tears are rolling down my eyes. There are tears rolling down my eyes. It's just an expressive way to say that you are crying, perhaps a lot.