You don't have to accept any of it. If I were you and if I was young, I'd move back home and date others. When he's done with school he can try again if you're free.

He's known he wasn't going to graduate when he told you he was, I wonder how long he waited to tell you.

Don't put your life on hold for ANYONE. Keep it moving. If he can catch up, fine, if not oh well.

It's also possible he won't graduate in December 2018 if he doesn't pass all his classes or can't afford to take the ones he needs, so there is no guarantee he's done then either.