I cant help it: Im in love with a married man?

I am love sick over a married man. I do fight the feelings. I know I cant have him. I just cant stop thinking of him. I cant stop wondering what it would be like to be with him. I am so desirous of him sexually that I cant concentrate at work. He acts like he likes me too. He wants to sit by me when we are together with a group of friends. He told me once that I was his favorite. I have caught him staring at me more than once. I have been ignoring these feelings for about a year now, but they are overwhelming me. I wanna talk to him, sleep with him, I havent said anything to him that would lead him to believe I have these feelings. I always act like I am friends with him and everyone else and when we talk it is strictly business. I am handling it right on the outside, but inside I am a wreck. He is dominating my mind. Does anyone have any suggestions for how I can get this man off of my mind. I am head over heels in love with him