This article is derived from the ESV Expository Commentary on this chapter from 2 Corinthians. The short answer about Paul’s thorn? It’s not important exactly important what it was, but rather, the lesson to be learned in how to handle tough things God allows us to go through! From Crossway.org……

https://www.crossway.org/articles/what-was-pauls-thorn-in-the-flesh-2-corinthians-12/