Admitted unhealthy obsession with a celebrity

I am a believer who has an unhealthy obsession with a celebrity and I wish to overcome it. It is unhealthy because thoughts and images in my mind have woken me up late at night once. I am bipolar and this is during a manic phase. I am no longer manic but I hope that I won't become depressed over it. I am embarassed to even mention the man's name. I have obsessed over a man in the past and it wasn't something that I am proud to admit. I don't wish to obsess over this man. I even have impure thoughts about this guy and I as a believer know that it is just no longer a crush. An obsession may start out as a crush but I know it can get worse over time and I don't want that. I don't know how to have a crush on someone.