I'm not sure what "it" means in this sentence.

Rebecca

I'm guessing that "it" here refers to the action mentioned just previously, which is walking into the metaphorical "fire of love." When "it" is used in a sentence and the meaning isn't immediately clear, it's most likely referring to the action or idea mentioned just previously. Ex: A: Where's the car? B: It's in the garage. Ex: A: Look at that cat! B: Wow, it's so cute.