How to get someone out of your head?

I met this guy and only saw him sometimes... Well since school started back up he is living with his parents again three hours in a different town. The only time I see him is if I'm outside walking around and if he's over his sisters.. He told me the only reason he sits on his porch is because of me. He said he liked me but I'm not sure. Me and his friend did something mostly just made out hugged and held hands.. But Alex never made the move ever.. Well he wanted a kiss but I never gave him one.. But I did his friend.. I just don't understand.. I think I made a mistake by kissing his friend in stuff because Alex is stuck in my head.. I can't call him because I deleted his parents number.. And Ryan is ignoring me... Because I can't make up my mind.. I think I really do like Alex... But I just don't know what to do... I don't know when I'll see him again.How to get someone out of your head?
Think of somebody else...