9-1-1 star cast Rob Lowe announces retirement today°BREAKING…..

Rob Lowe Was ‘a Wreck,’ ‘Like a Puddle’ When Son Matthew Went to College: ‘Tears Were Streaming’ (Exclusive)

The ‘Unstable’ star tells PEOPLE that Matthew leaving college felt “like the end of this wonderful journey that I had as a father with Matthew and with Johnny”..

It was anything but easy for Rob Lowe when his eldest son, Matthew, left for college.

The Unstable star recalled to PEOPLE the “brutal” experience of flying with Matthew — who turns 31 on Sept. 24 — and wife Sheryl to Duke University to help him move in for his freshman year of college.

“It brought up a lot of stuff,” he said during an interview for his August PEOPLE cover story. “And I thought, why is this affecting me so deeply? Because Sheryl was, I mean, not unaffected, but she wasn’t me.”

“I mean, I was like a puddle. I had to wear dark glasses on the plane because tears were streaming down my [face] the whole time,” Lowe, 60, admitted. “I couldn’t look at him sitting in his chair, in his little seat with a little book bag. I couldn’t do it… It’s triggering.”