How hard should you fight?

My mom says life will have a way of working itself out that in the end maybe life holds a surprise for me. That i'm living threw a hard time right now, that all my friends are going away and that's why i'm so sad. He's got a new girlfriend and a new cocky attitude and that's why i'm sad. All of a sudden i'm not allowed over there, people might get in trouble if he were to find out. Bad jokes and the over all demeanor has gone to shit. I thought he'd be my friend for the long haul, there until the end for each other, like bestfriends are supposed to be. I told my mom that sex changes everything, or the promise of sex anyway, and two weeks into this the we mentality has already begun and just like that he's gone. I lose. Game over. Should i fight? Should i just keep my mouth shut and leave things at that. Just fond memories of a person that i thought was a kindred soul. Step aside and make way for the new and improved model because last year's is old and busted, a green 98 neon that's no longer road worthy. that's me.