How do I stop obsessing?

I am a 32 year old woman, married for 8 years. My husband & I have a wonderful relationship (no fighting, no cheating etc., just happy). But I've  developed a crush on someone else. Lately, I'm embarrassed to say my thoughts have become obsessive. The worst part; this person isn't even real! It's Daryl Dixon. I want nothing to do with the actor Norman Reedus, it's just the character Daryl. He is ALL I think about & it's really interfering with my life. I don't know how to stop. I have always been a very rational person & have no history of mental illness or anything like that. I really don't understand why I feel this way. I've never been obsessed with a person before. I just want to stop thinking about him & go back to the way I used to be. Please don't be mean to me about this, I realize it is not healthy & I just want to stop thinking about him. Any advice would be greatly appreciated.