Writer - Need help with three words I plan to use in manuscript

[Maria Levato]

Hi,

I'm hoping someone can help me out here, if that's alright. I'm a romance writer and I need to clarify the correct way to convey what I want to. The idea is to use this as a term of endearment, so that's something to keep in mind as you read the rest of this. 

In English, it'd come out "my fire." Contextually, I'm trying to say "my passion".  Is there a Greek word or words that could express this sentiment in a term of endearment?

Thank you in advance.