I(23m) have been dating my girlfriend (23f) for about 10 months now, with an overall great relationship with ups and lows. Last month she received a BPD diagnosis from her psychiatrist,  meaning that she may  have been misdiagnosed with ADHD or Bipolarity for most of her teenage and adult life. By reading about BPD on articles or some lecture found on YT I've come to better understand some of her behavior that really bothered me, such as abrupt changes on Idealization and Devaluation and other emotional reactions to certain things that I have difficulty on understanding the cause or intensity of the triggers. 

She has been trough a tough month, dealing with Academic, Work and familiar stuff, so she is going trough a lot of stress, which in my understanding is accentuating her symptoms.

While I always try to be supportive and understanding of her emotional status, I've been having difficulty to find ways to properly help her (were I can) or generally being a supportive partner to someone with BPD.

I would like just to know ways or general stuff I should know to better be there for her when she needs, while also keeping myself in the right place of mind during the periods of devaluation.