The speaker is completely overwhelmed by love, or at least a powerful infatuation. Everything about the person they're describing turns to gold: her eyes, her laugh, her smile, and finally the speaker themselves. Gold stands for warmth, beauty and worth, but here it also takes over. It gets into the speaker's lungs and makes it hard to breathe, so the feeling is as dizzying as it is pleasant.
The middle of the poem is full of contrasts. She is "despicable, desirable, deadly," and the speaker shivers "to the bone," which suggests that attraction and fear are tangled together. Then the mood clears. The speaker can "see again," and misery disappears. She becomes the sun, the moon, the flowers and the air, so she is almost the whole world. Even the "burn" in the chest sounds more like passion than pain. The short last line, "We are golden," settles into something calm and shared, leaving a bright, intense, slightly breathless mood.