A good song about being in love with someone that you try so hard not to love?

So me and this guyyy have been on and off alot for awhile now since
febuary. i really love him alot, and he loves me too. but whenever we
break up he's automatticly talking to someone new. he has/had tons of
friends that are girls that he flirts with ALOT. he always tells me
how im different and hes never felt this way about a girl and all
that. but it's so hard to believe him. trust me if you really knew the
whole story you'd get it.

songs i got so farrrrr;
hate that i love you - rihanna
p.s. still not over you - rihanna
just so you know - jesse mccartney
i hate everything about you- three days grace
twisted - carrie underwood
taylor swift - tell me why ,  Breathe.
kelly clarkson- already gone
selena gomez  the scene- my dilemma

thankss please help!:)