The pilot stated that after takeoff, he experienced a primary trim failure and continued to the destination using secondary trim. The pilot stated that during final approach, he had difficulty visually locating traffic, and noticed that his airspeed was too high to lower the landing gear. The pilot continued to look for the traffic and "continued working the trim." In the landing flare, he heard "an unusual noise like something scraping," performed a go-around, and realized he had not extended the landing gear. The pilot then extended the gear and landed without incident. Inspection of the airplane revealed substantial damage to the airplane's fuselage.