I can see how what she says has some truth behind it. It seems they don't see what they're missing until the lose you fully.
And what he's talking about (D) equates to him leaving anyways, maybe it wouldn't hurt to give him that push out the door and let him free into the world. I don't expect it would be easy but it might actually give you some piece of mind to have him out of your hair and to be away from his roller coaster a bit.
Might be worth considering.
W:32 M:26 T:5 yrs M: 3 yr BD: JUN 2016 W Moved out: early JUL 2016 W Filed for D: mid JUL 2016 EA: 06/16? PA: 07/16 Moved in w/ ow: 07/16 D final: 10/16