Possible meanings for "outside" are 1) "outside of our bodies" or 2) "outside of the church." The word "inside" refers to their inward emotions. AT: "by conflicts with other people and by fears within ourselves" (See: [[rc://en/ta/man/translate/figs-explicit]])
Paul received comfort from knowing that the Corinthians had comforted Titus. AT: "by learning about the comfort that Titus had received from you" (See: [[rc://en/ta/man/translate/figs-explicit]])