Should I stay her friend?

One of my friends I have known since 5th grade. I am now in 7th. So 5th and 6th grade were awesome! We would spend the night at eachothers houses, we would go to events together, and hang out all day everyday, even at school. But last year we had like all classes together. This year, we are all split up and we have 0 classes together, literally. So now, me and her don't talk. And she doesn't even invite me anywhere anymore or try to talk to me at school. I usually have to be the one who starts the conversation. And I'm starting to get the feeling that she doesn't want to be my friend anymore because ya, we talk sometimes, but it's not really anything anymore. And it bugs me that she's always with this certain group of people everyday and loves them like best friends and all, but never even has time for me! And what really annoys me is that like 2 or 3 months ago, we were talking about it, like how we don't hang out anymore,and so she sent me a txt saying that I was really her best friend and none of the other people she hangs out with. But best friends act like best friends, not strangers. That's why I'm so confused right now. I mean if you actually get to know her, she's like the nicest person you will ever meet, and the only reason why she's doing this is because she doesn't know I feel that way. Should I talk to her about it? Because I don't want to loose her as a friend but I also don't want her to keep pretending that I'm her friend at all if we never hang out. Also, I invited her to go camping with me and we leave tomorrow for 3 days. And something came up that's on the same date and so her dad's still thinking about it because she told me she really wants to go and I want her to as well so we can actually hang out since it's been a long time. But I don't think she's going if he's waited this late so I'm sad about that. So should I still try to hang out with her and just talk to her about it or just leave her all behind? Because I am so confused right now and she always has friends. I don't want to lose her because I don't really have any friends cuz I got into an argument with my other 2 friends yesterday, so if I say bye to her, then I'll have no more friends left.....................I'm sad right now.............................so WHAT DO I DO PLZ!!!!!!!???????