Early days. Keep it gentle and trust the process.
Look how far you have all come.
He is talking to friends online.
A F2F opportunity is happening soon.
He is proactively seeking emotional connection with you by openly talking with you - sharing and showing his vulnerability. This is where he will reflect, change and grow stronger.
He has chosen to come home and stay home.
He has taken his emotional and physical space from her by being at home, leaving his job and even avoiding school.
Although the last two are problematic these actions indicate the fear, confusion and emotional turmoil and cognitive dissonance he finds himself in.
Remember he repeatedly said he was “scared” - fear is paralysing and “flight” or withdrawal is a standard survival technique.
He is now processing the negative stuff and telling you. That’s important and testament to his love and respect for you.
Let him “debrief” he has been through an emotional trauma - he got stuck into the vortex of an emotionally abusive RS and enmeshed in that dysfunctional family.
He is probably still reverberating and trying to make sense of it.
He is still in it but he is slowly separating.
Don’t focus too far ahead on them splitting up - just look at helping him to maintain the emotional and physical distance so that he can recover.
He lost himself in this. This has been very overwhelming.
Slowly he will find his own sense of self again.
Talking to you is a huge positive step. Don’t probe, but always be emotionally available - always validate everything he says - gently reflect / repeat it back with his own words “Yes of course you must have felt x, I can see why you would be hurt / confused / etc” Don’t judge her or him or the RS - let him to that.
Is he still doing his sports? Exercise is really important for low mood and this is also a huge part of his identity.
It’s great that he has work experience sorted - that should really help with a total change of scenery. It is all shifting in the right direction.
Keep an eye on his mood and keep speaking with school.
You have done really well to have got him to this place where he is today. It might well continue to be a bumpy ride for some time - but it’s the beginning of the end.
If they do split up it will likely be plenty of fireworks and back and forth - I doubt it will just fizzle out. He will need you to be a calm, non judgmental, supportive safe haven during that time.
I hope that you are doing lots of restorative, indulgent, self care and seeking support from trusted family and friends - because you need it to get you through - you are not dealing with normal here. You, your DS and your family have had a brush with an unhinged, toxic, dynamic. You just need to extract yourselves out of this calmly, slowly and safely.
Don’t engage with her DPs.