Trying to convince her to try a long distance relationship

This girl and I started talking and hanging out a lot about 5 months ago. She told me back then that she wanted to be in a relationship but I wasn't sure about it at the time. I really liked her but I wasn't sure that a relationship was what I wanted. Time moved on and we continued hanging out. About a month later, she started saying she had stuff to do so we couldn't hang out, and I was ok with it, she lives a pretty busy lifestyle and I didn't think anything about it. Until a couple weeks later one of my friends said he saw her going home from her ex boyfriends house fairly early in the morning. I asked her about it and she told me she wasn't there, but that she had to go into town to get some stuff at the store. She started to not want to hang out even more, and so I asked her again, and she said that she'd been staying the night with her ex off and on. The reason they broke up in the first place was because he was cheating on her with several different girls and she found out. We still hang out very rarely now, and I'm pretty sure I'm in love with her. She still goes and stays with him every now and then, and she recently found out that he is still cheating on her with several girls. She tries to act like she doesn't care, but I know that it hurts her a lot and I can tell. How can I convince her to leave him for me? I would never hurt her or cheat on her, I'm way too scared to lose her. She says it won't work because we will be going off to college at the end of the summer and we will be 2 hours apart, but I don't want to be with anyone else, I want to be with her. I'll do anything to be with her. I want to get her to realize that I'll do whatever it takes to make it work, no matter how far away we are.

You can't start a good relationship when the other person isn't interested. If you're starting from a point of needing to change her mind you're just setting yourself up for continued heartache. It's also not fair to the girl. She has the right to make her own choices whether you think she's making a mistake or not. Please find a way to move on. Eventually you'll feel ready to look for another girl to care about who does want to try being in a relationship with you.