From Fox News:
Patrick told [Sixty Minutes] his grief became so overwhelming that he questioned whether he would live to see another birthday. “There was a time where I didn’t think I would live to see my 35th birthday, and I was completely fine with it,” he said.
Patrick later left Duxbury for New York City, where he could grieve without being recognized. Five weeks after the move, on what would have been Callan’s first birthday, he went to St. Patrick’s Cathedral, lit a candle and told his son, “I love you, buddy.” “And I walk out on Fifth Avenue and I start crying my eyes out, and nobody cared,” Patrick recalled. For Patrick, being able to cry without drawing attention was exactly what he needed.