The pilot reported that he was conducting an instrument approach in instrument meteorological conditions. Upon reaching the decision altitude, the front-seat passenger reported the runway was in front of the airplane. The pilot looked up from the instruments, but could not see the runway out the windscreen or the side window. Referring back to the flight instruments, the pilot noted that the airplane was level, but he was unable to determine the airplane's altitude and did not know where the airplane was in relation to the runway. The pilot then applied full engine power and began to climb the airplane; however, the airplane's right wing impacted a light pole. The airplane immediately pitched nose-down and descended into terrain. The pilot reported there were no mechanical malfunctions or anomalies with the airplane that would have precluded normal operation, and that the accident could have been prevented if he had immediately executed a missed approach at the decision altitude.