I disagree.
I think it's about a relationship that gets split up because the girl is changing state. She decides to end it because she doesn't think their relationship could continue long-distance, and suggests that they'd both end up finding other people. But he feels she's the only one he needs and that as proof she could even "tie up [his] hands".
I get that idea from the line "please don't believe me when I say I don't miss you". I reckon that he feels like he has no choice but to accept it and even claims not to miss her, so that she doesn't feel bad, but he's really miserable over her.
I disagree. I think it's about a relationship that gets split up because the girl is changing state. She decides to end it because she doesn't think their relationship could continue long-distance, and suggests that they'd both end up finding other people. But he feels she's the only one he needs and that as proof she could even "tie up [his] hands". I get that idea from the line "please don't believe me when I say I don't miss you". I reckon that he feels like he has no choice but to accept it and even claims not to miss her, so that she doesn't feel bad, but he's really miserable over her.