How do I persuade a girl to break up with her present boyfriend to be with me?

So, i'm in this pretty messed up situation right now.

I fell for this girl who has a boyfriend right now.
The problem is,
I have been going out with her more often than she does with her boyfriend.
And just last week, she came upstate to stay with me for a week,
and we held hands, hugged and even kissed.
I need some advice on what I should and should not do in this kind of situations.

Well, she's pretty confused herself too,
and I think that's my advantage,
therefore, I need some strong advice on what I CAN and SHOULD say to her via text/call since we're pretty far away from each other right now.

I hope you guys can help me,
because I have no one else that I can rely on.

I won't let her go,
because I really do love her.
So please help me,
the more advice the merrier thanks!