i don't blame you for being torn on what to think.. it seems that on one end you want to follow you instinct and hope that determination and persistence leads you back to where you once stood.. on the other hand you're fighting what seems more and more like reality of him showing more signs of not coming back..
however from the facts here, it seems he really means it.. the reality is if it didn't work out all those times, it's probably not going to work out at all.. I don't know the details of everything you and him shared in those years but according to him, it doesn't seem to be anything special enough to keep; maybe enough to remember and nothing more.. take a few deep breaths, calm yourself for a minute.. and really, take a very broad look at everything that happened.. so he was special, but can you find someone better? remember everyone you've met.. everything u've heard about relationships.. remember that there is no rule to life, life is random.. and things more than likely happen for a reason..
also, by you pleading him to come back, you're lowering ur value to him as a person.. it's kind of tricky.. but it's kind of like the chinese finger trap; although hard to resist but the more you plea, the less likely he might come back to you.. if you want, compose yourself as much as you can, tell him honestly everything you feel, and be brief about it.. and let him go.. just as long as you say things that will help you move on..
i hope this helps..