Brie's poem is about the aftermath of a relationship that meant everything to the speaker. The feeling is painfully split. Some days they want to wipe out every memory of the other person, and other days those same memories seem to be the only thing keeping them going.
The middle lines hold the sharpest contradiction. The person who once made the speaker "wanna live" now makes them "wanna die," and the speaker admits that without this person they "could never feel alive." The love and the hurt come from the same source, so the speaker can't separate them.
The last two lines set mind against heart. The mind wants to forget, but the heart clings to memories because they're "all I have left." The mood is raw, sad, and a little desperate. The plain, unpolished wording, with its loose spacing and lowercase "i," makes it feel like a private thought written down in a low moment.