Yeah, that makes sense.
Oddly enough, I'm the one that took most of those steps (after finally accepting his persistent behavior and going out with him), I'm the one that first brought up marriage.

Perhaps that's a little hasty considering how difficult I find it trust?

I am worried that he'll leave me, and I honestly don't understand why he hasn't. Most people would have, I'd think. Now that we're living together, he receives the brunt of my bipolar issues... moreso than my parents. I don't understand him putting up with it.
But then again, I guess I put up with his addiction to gaming (he does so pretty much all the time).