I have a different interpretation. I think it's plainly about having a crush on someone, maybe a fling, but ultimately the other person rejects you as a partner because they don't think you meet their standards. He's obviously distraught over the rejection, but he refuses to feel worthless about himself over it. Detroit, mousy homes, and catacombs are the singer describing himself as a humble type, not very polished or attractive as a partner. But he thinks he has a skyline, or desirable qualities, if the other person could just see it. Maybe the timing isn't right in their lives at that point so he wants them to try it again in a year.
I have a different interpretation. I think it's plainly about having a crush on someone, maybe a fling, but ultimately the other person rejects you as a partner because they don't think you meet their standards. He's obviously distraught over the rejection, but he refuses to feel worthless about himself over it. Detroit, mousy homes, and catacombs are the singer describing himself as a humble type, not very polished or attractive as a partner. But he thinks he has a skyline, or desirable qualities, if the other person could just see it. Maybe the timing isn't right in their lives at that point so he wants them to try it again in a year.