Help!!!

okay well, I really need help because I'm in a pretty bad situation at the moment, see I really really like this guy Jon, he's so amazing because he's like an amazing version of myself! see its awsome and he somewhat likes me back, but the problem is major, he's dating this girl, Tori and she's cool and really pretty and I would probably like her if he wasn't around but he is and I only like him, but he wont dump her for me cuz he's "in love" but he's the only reason why im not dead and he says when hes sad only i can make him smile. I somewhat feel like he could be the thing that's been missing for the past few years but I cant tell him how I feel because of her.