I have read numerous interpretations about the scripture listed above. One scholar thought that Paul struggled against lasciviousness and another thought that he was burdened with arthritis or another painful health issue. Another writer assured his readers that Paul's 'thorn in the flesh' involved weight issues and that he had to live with continual frustration because no diets worked for him. I guess we all tend to project different maladies upon Paul, based on our experiences.
Recently I was reading in the Old Testament and came across several verses that gave me a new way to think about Paul's affliction. Here's one in particular:
But if ye will not drive out the inhabitants of the land from before you; then it shall come to pass, that those which ye let remain of them shall be pricks in your eyes, and thorns in your sides, and shall vex you in the land wherein ye dwell. Numbers 33:55
Maybe Paul had to put up with an individual who really tried his patience. Anyway, the rhetorical links support that as a possible conclusion. It's interesting to think about.