You know, Leslie is right. Somewhere something with your son went off, he’s upset. I spend a lot of time researching adult relationships with adult children and most kids need their parents to just own up and apologize even if you personally don’t agree. That’s what it takes and you’d be shocked by the 99% of grown adults on one hand wanting their child, but also being stubborn people who cannot apologize or take responsibility for anything they may have done however unknowingly that hurt their child.
He’s got a rapt audience with his new gf and her family. Take some space and think about it. see a therapist and work out what you need to say to get him back sooner.