I can't go over to see her, she lives an hour south of me (around Boston) and I don't have my own car to do that with. The relationship is usually dependent on her to drive, which is unfortunate but usually works pretty well.
Anyway we discussed this yesterday and had a great day apart from the discussion on top of that. This happens a lot though, but I have it on good faith that the discussion we had made a difference. Essentially, she was angry for reasons unrelated to her trauma, and unrelated to me, so she wanted to clear that up first. I told her that pushing me away to "spare me" from her bad feelings is really just destructive and explained why. After that I got her to agree with me that we need to try something else when we get in those kind of moods (cuz I sometimes do too): I told her instead of pushing me away, she can give me a quick phone call, sound understanding and sensitive about it, and just let me know that all is well between us and the source of the bad mood is external to the relationship, and to just mention that either of us want to be alone for a while and we'll be fine in the morning/a few hours. She liked the sound of it and thanked me immensely.