The speaker begins by quoting a familiar piece of advice: you can't love someone else until you love yourself. Then comes a one-word rebuttal, "Bullshit!", which sets the tone. It's blunt, defiant, and a little raw. The speaker says they have never loved themselves, yet they clearly love someone else, and that fact is offered as proof the saying is wrong.
The last line is where the poem softens. Loving this person is so strong that the speaker "forgot what hating myself felt like." That doesn't mean self-hatred is gone for good, only that it has gone quiet for now. The trailing ".." suggests a voice trailing off, maybe still amazed or a bit unsure. The mood is a mix of anger at tidy advice and tender gratitude toward someone who, for a while, has made the speaker's inner voice kinder. The poem is short, but it shows how love can feel like relief as much as romance.