I've read the responses. I just feel that instead of listening to her, I read too much into peoples opinions here.
Thanks to the few of you who were actually caring though.
We had a lot of heart to hearts since and actually, she had and has a hell of a lot going on, which anyone would find hard to deal with and because we're so far apart, she just needed someone there for her. Nothing more than a kiss happened and once I go out to college we're going to be in adjacent states, meaning I can see her regularly and we can be there a lot more for each other in person. Before we met, we knew we liked each other, but we realised we couldn't be there for each other in person, so we dated other people etc. After we met, perspective was thrown out the window and we forgot how hard it really is when you really need someone there for you, but you know you won't see them for months and months.
I kissed another girl since we decided cooled back to friends between now and January when I move out to the states. I told her, as she was honest with me so I was honest with her, and I think now she understands how I felt. I didn't do it to get back at her, I did it because the girl made me feel wanted.
Yes, to the myriad of you that told me this, there are plenty of girls out there and yes, I could have walked away... but that's the easiest thing in the world. When you have someone you actually love, you fight til the fucking end. Maybe she will hurt me again, but I don't think she will. If she does? I know that I gave it everything and that there was nothing more I could do. I'd rather know that there was nothing more I could do, than be wondering 'what if?' in 10 years time.
She's flying to see me in January and we're gonna take it from there. We're gonna take it in turns to visit each other each month as we planned before this happened. We haven't talked about next summer yet, but she planned to come back to live with me when I go home over summer for 4 months. So we shall see what happens then.
And yeah, Kingsnake she did have a boyfriend, and I had a girlfriend. We both were very open about who we were dating and our sex life. We're both not dating anyone now and we don't plan on dating anyone now as January is only a month and a bit away.
Thanks to the rest of you though. I appreciate it a lot.