Why would either of you want to marry? You're both liars and cheats. Getting married would be an utter disaster that would ruin both of your lives. If he's treating you like a stranger now, then, literally, thank God for sparring you from the biggest mistake in your life.
Quit chasing after him because he's no one worth marrying. And really, currently you are not either. You can each, apart from one another, learn to quit being this way. But if i were you i'd move on and stay OUT of any relationships until you have matured enough to behave correctly in a relationship.
And that fact that you are continually on and off only verifies it. You think you can handle the commitment of marriage when you can't even stay together while dating?
Lastly if he throws things in your face and blames you for everything, then why would you Want to be with him? He's a jerk on top of all the other crap. Also, him throwing your past in your face constantly and blaming you for things he's just as guilty of is a red flag for potentially abusive behavior in the future. Some could say it's just the beginning of it.
Leaving someone after such a long time is scary, but not everything good for you is easy. It's time to mature mentally, emotionally and spiritually. Walk away and don't look back. Spend your time growing closer to God so He can grow you into a right person. Not trying to be mean by saying all this, but it sounds like you need to be shocked out of your trance and see what's really going on, and that's why i was so blunt.
Hopefully you heed this and realize you need to change yourself, and forget about him, and set your eyes to God and let Him grow you into the kind of woman He intended you to be, not the one you are. Wish you well.
