The pilot reported that he was landing long on a grass airstrip near his home. During the landing roll the wind shifted from a crosswind to a tailwind, which pushed the airplane down the last part of the runway. The pilot commented that he tried to intentionally ground loop the airplane before it went over an embankment at the end of the runway, but was unable to gain any authority over the airplane due to the wind. Subsequently, the airplane traveled 20 feet down a small embankment which bent the front fuselage of the airplane up into the cockpit area. The pilot reported no mechanical failures or malfunctions that would have precluded normal flight.