From the album Ö
This is a plea disguised as a promise. The narrator keeps saying she'll never leave him lonely, but the real message is don't leave me lonely, and by the end the reassurance has completely flipped into a threat. Physical touch is the only proof the relationship exists, and morning is when that proof disappears.
I love you all the time / You know the hold you got
She names the hold he has on her before offering anything about what she has on him. The power imbalance is already clear. This is supposed to sound devoted, but it reads more like announcing she's trapped.
I'll never leave you lonely / Don't leave me when it turns to morning
The promise and the beg land in the same breath. She offers to never leave him lonely, then immediately asks him not to do the exact thing she just promised not to do. The reassurance is actually a negotiation, and she's losing.
Look the other way and you'll lose all of me
This line gets repeated six times by the end, which turns a warning into something closer to begging or even self-hypnosis. If you were really the only girl he needed, you wouldn't have to say it this many times. The threat only works if he's already looking the other way.
I want you all the time / Even when you don't say
He doesn't say it back. That absence is doing all the work here. She wants him even when he's silent, which means his silence is constant and she's learned to want him through it anyway. The song never lets him speak, because he probably isn't saying much in real life either.
The only girl in the world that you need
Repeating this claim six times in a row stops sounding like confidence and starts sounding like she's trying to convince herself. The more she says it, the less true it feels. I'm not sure she believes it anymore, but she needs him to.
The song starts as a love song and ends as a hostage negotiation where the hostage is also the one holding the gun. By the time the post-chorus loops for the sixth time, the narrator has talked herself into a corner. She's the only girl in the world he needs, except she has to keep saying it because he's not.