I'm glad my verbal meandering had value for you. When I say "cringe" it's only because it sounds kind of cliched. The line 'to the bone' is quite common to me so it is bland is all. I"m not saying the sentiment is what made me cringe, just the way it was expressed wasn't as good as the other parts of the song so it stuck out.
"move 6000 miles and leave the place that had become my home" I feel like this could be an important thing to mention. That is a long, long way to move from a place you loved and it makes me immediately empathize with you. That kind of distance can be used to emphasize the depth of longing as well, like 6000 miles of homesick in a way.
"unsure whether it's my home and my old life that I miss more or the ex" If this is the main conflict, maybe you should explore this more, flesh it out, make it feel that way. I can see this being a great place to write some wonderful lyrics. Perhaps the song can express your struggle to figure it out. Right now I don't get the feeling you miss your old life so much as just him. The chorus is acting to repeat and emphasize the conflict but it only mentions him. Is the conflict about whether you long for the home you had or for the ex and you're not sure? If so, the chorus doesn't really suggest it.
I think fundamentally, we writers are all expressing commonly shared experiences. However, making it compelling means expressing it in a personal way. While we can describe the experience accurately in a generic way, that doesn't make us feel it. It's the details that we fall in love with, that end up evoking the feelings and being a vehicle for meaning. It's difficult to do well but I think it's essential. That being said, writing a poem and lyrics are very different, one can't entrust emotional impact to the music when writing poetry.
Good luck, I really hope you keep at it!