I've tried several different pads and ended up going back to OEM every time. Between commute, canyon carving, 2 up, long haul, and track days, never had an issue. On the occasional really hot track day, I'd get some brake fade towards the end of the day. Nothing that skipping 1 session to rest/hydrate couldn't fix. The lowest I ever got was about 14k miles with several track days, a couple of long hauls, and 12k miles of heavy commutes.
I suspect something is wrong with your brake fluid, master, lever, calipers/ rotors, or lines. Have you fully flushed out and bled your lines with dot4? Replace the lines to steel braided? Clean your calipers and make sure they are working freely and smoothly? Clean the rotor buttons? Clean the brake lever pivot and lube? Adjusted correctly? Check the diaphragm in the master cylinder to ensure no leakage, poor seal, or trapped air? Check the bleed screws to ensue no leaks or air getting through?