At any rate, she informed me after another few weeks that her feelings hadn't returned ever after the first breakup, so we broke it off mutually at that point, and decided to stay friends. About a month after that, I asked her and found out that she was hooking up with the guy she cheated with while saying she wanted to be friends with me. At this point, I just cut her off completely, but I'm honestly not sure how to deal with it personally, and I keep wondering why my judgment was so bad. I don't know.
Sorry again for all the info, but yeah, any advice is appreciated.