Guys, thank you so much for the information and support. I spoke to her and got closure, it's over, and I finally feel at peace. She's sticking to her story that something "snapped" during our fighting over intimacy, and she no longer felt the same way. I'm going to wonder if she was just lying to spare my feelings that she loved me up until then, or if she's telling the truth, or if she's telling the truth and PTSD made her run. But that's something I'll have to live with.
I have one final question about numbness: I had the conception that it only applied to her feelings towards me, but it occurred to me that you might be talking about total emotional numbness in general. As in, you don't feel happy, sad, or anything else. When you say you can get "numb," does that mean all feelings? Or, in the case I've been talking about, is it only numbness of intimate feelings towards me and our relationship?