Truck capacity

I have a 2013 F250 Super Cab 8' bed with the camper package. 10,000 pound GVWR, 6,200 rear and 5,940 front. Our camper must be roughly 3,000 pounds wet and the tongue weight of our enclosed 6x12 probably about 350 pounds. Stableload's blocks for the factory upper overloads and Timbrens SES (heavy-duty axle bump stops) have been added. The truck has factory anti-sway bars. I swapped the factory 17" steelies and SUV tires for 18" Aluminum wheels with wider tires for more capacity. I feel like our rig is at its limits. I considered going to a tandem axle 7x12 or 7x14, but I'm a little scared of a larger trailer/more tongue weight. Concerned enough to think about selling the F250, take a little loss, and getting a dually to feel confident with a 7x14. Maybe I'm a big sissy, but when I see the weight on my rear tires, it kinda freaks me out.
EDIT: All that hitch apparatus is going to weigh a few pounds. We don't need an extension or a WDH.