Need it off my chest

My son and I got in a huge fight this afternoon. He was so enraged that he packed his stuff. He's still here now but I think the "camel's back" is broken.
I knew he wasn't gonna live with his parents his whole life but why does my gut say that if/when he leaves I'm never gonna see him again?
I had to write this 'cause I can't sleep because of that dreaded feeling and losing what little I did eat today hasn't helped either.
sometimes being a parent SUCKS!!!!!