It is not the camber. You have lowered your car so much that it is beyond the damper travel range of the coilovers. Once you raise the cat back up, the car will feel less floaty. I had -3.5° camber and the cat was not floaty when I drive from sydney to melbourne at 110 km/h eventhough it looked worse than the pic above. Mine looked like a V8 supercar in reverse.