Jamieson, Fausset and Brown on 2 Corinthians 11:28

28. without--"Beside" trials falling on me externally, just recounted, there is "that which cometh upon me (literally, the impetuous concourse to me of business; properly, a crowd rising up against one again and again, and ready to bear him down), the care of all the churches" (including those not yet seen in the flesh, Col 2:1): an internal and more weighty anxiety. But the oldest manuscripts for "that which cometh," read, "the pressure": "the pressing care-taking" or "inspection that is upon me daily." Alford translates, "Omitting what is BESIDES"; namely, those other trials besides those recounted. But the Vulgate, Estius, and Bengel, support English Version.

the care--The Greek implies, "my anxious solicitude for all the churches."