This is such a heart wrenching problem and I apologise in advance for the "hard love" I am about to propose. I am taking your mental health as a priority.
Firstly, I'm 66yo, have 2 adult daughters one I am close to and one, following many years of narcissistic behaviour mirroring her mother, I said goodbye, again for self preservation (I had one suicidal event). Talk about pain.
I suggest you make a plan. It could be 3,6,9 months, no more or he'll think it won't happen. Your plan can include things like-
- Travelling in a camper van
- Moving into a one bedroom unit
- Moving interstate
Etc. Whatever you plan is for your reasons, in fact one lesson to learn is- you don't need a reason.!
Your son is an adult, he can work, he can work 2 or 3 part time jobs, he can volunteer to help needy organisations, he hasn't turned out to represent a man he should be- time to change.
Will you panic? No reason to. As an unemployed man with no where to live he can get rental allowance, team up with sharing a premises with flatmates like uni students do, pay equal portions of power bills etc and if he struggles... he can work at take away shops or get a security guard license. He can of course move in with dad?
I think by now you realise you've developed into an enabler of sorts, where mum will do it all for me. You feel used and this is in the prime of your life.
My prediction is, if you make a plan and give him a timeline, when move out day comes, he'll stay. But you'll need to make sure you are gone the next day.
I think you know what I'm saying. Love and care is a two way street even parents and their children.