By Aili NahasOriginal Source: people.comIn the five years since former Glee star Cory Monteithdied of a heroin overdose at age 31, his mother Ann McGregor has had time to plenty of time to reflect on her enormous loss.“A part of me died when Cory did,” McGregor, 67, tells PEOPLE. “My world stopped and I didn’t think I’d ever get up from it.”Monteith was just 13 years old when he became mixed up with an older crowd and began experimenting with drugs and...click here to continue reading