The pilot stated that the automated terminal information service reported that the winds were from the west at 6 knots. He entered downwind for runway 26, turned a long final at 500 feet, and planned to touch down just past the runway numbers. He noted a headwind as he approached at 90 miles per hour (mph). About 20 feet above ground level, the airplane suddenly sank. The airplane touched down hard in a nose-high attitude and the landing gear collapsed. The airplane skidded about 1,000 feet and stopped off the left side of the runway. The pilot noted that he normally flew an approach speed of 90 mph, and chose to do so because the runway was only 2,600 feet long due to a displaced threshold. He uses 100 mph in high temperature or gusty wind conditions. He opined that if he had been at 100 mph, he might have been able to stop the unexpected high sink rate prior to contacting the runway.