So when my gf and I got together, she was very understanding and open to learning about BPD and understanding my feelings and where they come from etc. But I think it kinda went too far? 

Basically, my gf has been struggling for like the last six months because every time I have an emotion, my gf feels it too. If I'm sad, she's sad, if I cheer up, she cheers up, then gets confused about the quick change, then is exhausted from how fast my emotions can change from one extreme to the other. She knows my emotions aren't always rational, and she's educated so it feels like absolutely nothing I say to her is helpful because she knows it already? 

I'm trying to hide my emotions from her now so that she stops struggling with the intensity, but that upsets her too? And it doesn't even work most of the time, she can tell when my emotions change literally from the way my eyebrow moves even if I try to not show anything. 

And I said she should maybe try reading more about being with someone with BPD, and dealing with the rapid emotion changes etc, and she said she doesn't want to, so that's confused me too because I don't understand why she doesn't want to fix this issue. But she's also at the point where she's not happy in the relationship because of this. So I really don't know what to do? 

Any advice is appreciated :) *
(* Aside from advice to break up, our relationship is very very good this is just an issue I'm not sure how to solve, as I'm not sure how to support her ?)