So I did some research and got some input from some other people, and I think I figured out what the dream means, mostly.
1. She was bleeding a lot, meaning that she is emotionally drained, and going through a lot of emotional pain
2. The fact that I was taking care of her and cleaning up the blood means that I am the only thing that can soothe that pain and make things better.
3. The empty candy wrapper means that she wants something (i.e. me) but she is not getting it, because other people won’t allow it to happen (Kaitlyn symbolizing her parents who pressured her into not being a relationship, as well as my sister, herself, who disapproved of our relationship)
4. After all those events, we left to go to school together. This could mean that she sees us together in the near future, as she only has a little over a year left of college.
5. At the end, we went to a concert together. This is a somewhat romantic setting, denoting that she still thinks of me in a romantic way (meaning she still loves me).
I thought this was pretty awesome.