Let go, dear... let go...
You've always known that it will be painful. The longer it lasts, the more painful it ends. So just keep at it, it'll pass sooner than you think. You don't have to, or have any, handle on this anymore, on him anyway.
Just remember when you feel weak, that he'll come by if he wants to. If he wants to...

(But that also hurts, no? Because no one's ever really, perseveringly wanted to...)