First, you sound like a really understanding and rational partner. I really applaud you for being so patient.
It seems like she is also very conscious of her condition, and that's great that she's trying so hard.
Realistically, I don't know if you can last several years of this. Something has to give. You could seek counseling for the "whiplash" but it would be like getting physical therapy for something you have to keep re-injuring every month. Has she exhausted her medical options?
And listen, I say this because I have some physical touch problems. I get overwhelmed by it and I often hate to be touched. I also suffer from depression and severe anxiety. And I dunno if I have a touch of Aspergers or what, but physical touch can be very unpleasant for me if I'm not in the mood. My husband also needs physical touch and sex to feel connected. And listen.... I touch him anyway. Despite my discomfort, I do it because I love him. We have sex 5x or so a week, because I see it as a physical expression of my love....regardless of whether I'm in the mood or feel like being touched. If I'm truly overwhelmed physically that day, then I will just attend to his needs and ask him not to be too hands-y with me. I try to find other ways, like teasing, to turn him on in case I don't want my body touched too much. I am 100% happy to do this because I am not satisfied unless he is satisfied by the relationship. It gives me pleasure and happiness to know that he is getting his needs met. The relationship isn't all about me. I do need a lot of emotional support and realistically he probably gives more than he takes...and that's partly why I have such a strong desire to make sure I'm not putting my moods before his needs. I guess I look at my mood objectively like "okay i'm currently in an anxious standoffish mood, but that's temporary and my love for him is permanent and his need is permanent, so I don't want to put this temporary mood that's based on some wonky brain chemistry before his very real emotional need."
The thing is that these are conclusions I have come to myself without being told. My husband has only expressed what he needed, and I came to the conclusion that I could meet his need before my own. And in return, when I meet his needs, he is empowered to meet mine. So I don't really know how you could ask someone to do what I do. Also, I'm really unhappy and dissatisfied by my moodiness and anxiety and dislike of being touched. I don't want to accept it as a limitation. I want to control myself, not live my life according to hormones. So this is what I do. My husband was resistant at first because he thought that I was doing something I didn't want to do to make him happy, but I explained that I'm actually unhappy when I'm unable to meet his need and I would rather push through what I'm feeling in the moment to meet his need than live with an over-arching feeling of neglecting him.
So that's me. everybody is different and capable of handling different things. I don't know what the answer is for everyone else. I only know that for me, the answer is fighting through the moment. I have to push back the mental block of "I'm in the dark pit of despair" and choose to live my life anyway. And in doing that, I have achieved a very happy and satisfying life and a happy husband. I'm not a weirdo who thinks I need to "please a man" to have purpose. I just want to give as much as a take.