[s8loud]

I don't think giving him an ultimatum would be the right way to go, cuz that would mean that the two of you would still be "together." Along the lines of what deej42 said, I think it would be better for you in the long run to just let him go. Even if he decides to marry you, that won't change the type of person he is, and you've had more time than most people to gauge that for yourself. And after you end it, take some time for yourself without worrying about who to "start over" with. With all due respect, it sounds like you have your own personal issues to contend with, and I would suggest you do that before exposing yourself to another relationship.