Du'a for relief from pain

بِسْمِ اللَّهِ، أَعُوذُ بِاللَّهِ وَقُدْرَتِهِ مِنْ شَرِّ مَا أَجِدُ وَأُحَاذِرُ

Bismillah, a'udhu billahi wa qudratihi min sharri ma ajidu wa uhadhir

With the name of Allah, I seek refuge with Allah and His omnipotence from the evil of what I feel and that which I am wary of.

Ṣaḥīḥ Muslim 2202. In the narration, "Bismillah" is said three times and the rest seven times.