I'm not totally sure if it's correct, but this is how I'm interpreting the song because it's what it means to me, right this second:
I think it's about a relationship that's ended, badly. The guy misses the girl horribly and would do anything to have 'just one conversation', but he realizes that he's already done everything he can ('but I can't change this'), and now the ball is in her court. He can't do anything more to make things right, she is the one who must make the effort to return to him. And meanwhile, he's just going to keep missing her.
I'm not totally sure if it's correct, but this is how I'm interpreting the song because it's what it means to me, right this second:
I think it's about a relationship that's ended, badly. The guy misses the girl horribly and would do anything to have 'just one conversation', but he realizes that he's already done everything he can ('but I can't change this'), and now the ball is in her court. He can't do anything more to make things right, she is the one who must make the effort to return to him. And meanwhile, he's just going to keep missing her.