I think this comes down to expectation and what you think of as "In love." Your milage from romance varies from couple to couple, and thinking that the glow you get from a new relation will last forever is just foolish. Here's a question to ask yourself: Are you failing to adjust expectations for the relationship as it matures, or have you decided that it is not something you want to continue long term?

If you find it's the first, and it's become something that you're comfortable AND (this is a VERY big and) content to continue with, if not particularly excited by, than you may need to adjust your personal expectations. This post is reason to believe this may not be the case.

If it turns out to be the second, then things are one hell of a lot more dicey. First, both of you need to have a conversation about expectations. The operative question is this: Is an indefinite future an expectation or a possibility? If you disagree on this, then I'd recommend finding somewhere else to live. Obviously, for you at least, it's not an expectation. If it's just the sort of thing where he thinks of it as just what's working for now, than be comfortable with that and reevaluate at the nearest possible juncture. If either of you are not open to being together forever, even just as an abstract possibility, than it's time to go. Make arrangements and leave. Be open, honest, and clear with how you feel, and I would recommend having NO contact with them for at the very least six months (maybe a year) after the breakup unless absolutely necessary. They are, if that is the choice you make, gone from your life.

I'm realizing that this is becoming a ramble. I could delete it and try to focus things down, but fuck it, I believe all of this. The thing is that I was with someone I was totally in love with, and she could never be honest about how she felt. She never really broke up with me, we just went on break one summer, moved into a two bedroom apartment that fall, and I just sort of had to put it together on my own. Point is, it's important to be honest. If you don't want to be with him anymore, than go. Just go. It will hurt. Both of you. There will be pain, but life is pain. Life is also joy, and excitement, and horror, and terror, and joy, and boredom, and simple contentedness. If what you have doesn't feel right, then change. You can do that. I believe that. I believe that you can find happiness.