Id not hold my breath on getting him back anytime soon.
And you shouldn't want to be with someone right now if they are unsure. Even if he suddenly reversed, you still shouldn't want to be with that person without reservations. Basically you're opening yourself up to the "i want you so badly i dont care what it takes" roll, which is bad news for you.
But you can keep things civil and open. My daughter dated a great guy a few years ago. Everyone in the family was sad when they broke up... not like we were trying to get her stuck with anyone... we all just liked him a lot. Just a solid guy.
Now three years later they are dating again. Still might not last, but the thing they both did was keep things civil and act more like friends than bf/gf for some time. She dated other guys, he dated other girls. Now they are trying it out again.
As for the note. Do whatever gets you though the night but id just not go overboard if you decide to do it. Less is more, and if you do it you should give it to an impartial guy friend to see if its overboard. But then you might have some things to say and that's your call.
I don't think there is any magic thing you can say to get him back. He needs some space for whatever reason (did he get much "guy time" when you were together or was it always you together?) and that's that.