I think it’s rule number one in the Addiction Playbook: never close the door on someone who cares for you.
You might need them someday.
For money, for sex, for a place to live.
Not saying this to be snarky, fbb, as I admire your resolve: how about making your own closure?
Say it in your head and out loud if you want to.
“It’s over. He’s gone. I can do much, much better.”