I have felt like this at times when it seemed there was more distance between us, or that I imagined she was being distant and cool. If I sense that someone is pulling back, I pull back 10 times farther. Experiencing the feelings (as with you) come later, when I'm alone.

I have no way of knowing if this is what's happening with you, but if it is maybe you can talk to her about feeling distant. It could be that she's going through a rough time of her own and it's changed something in your sessions. It's hard to know. It may not be about you at all.