One of the most difficult parts of managing my BPD is when I feel a negative emotion that's a normal and reasonable reaction, yet the intensity of that emotion takes it to a darker place that isn't normal or reasonable. This makes it almost impossible to judge when to express an emotion to people in my life or when to manage it on my own.

If my boyfriend does anything to let me down or upset me, I have a right to be hurt and angry, but of course often it manifests not simply as being mad at him but turns into rage and despair. Feeling taken for granted turns into being overwhelmed with the certainty that he doesn't love me and is being a terrible boyfriend. It's very difficult to stay grounded and remind myself that while the emotion I'm feeling is valid, the nature of it is a distorted and unhealthy version of that otherwise valid emotion. 

So when any person or situation in my life upsets me, I never truly know if I should try talking about it or whether it's a reasonable thing to feel, and I often end up burying a lot of things that bother me and never resolving them. It's so hard to tell the difference between unreasonable emotional reactions to a situation and emotional reactions that are reasonable but amplified by my BPD.

Any advice on this from anyone who's experienced something similar? 