I (36m) don't have a diagnosis, but fit the DSM IV and this reddit has really shown me some of my behaviours are classic BPD. So I hope people are happy to help. 

I tend to spiral when I get defensive and have taken something that's happened personally. I also have always had a dark sense of humour based on self deprecation. This used to sit well with my partner. 

Now, whenever I make a comment that's negative (even slightly) its received really badly, it spoils her mood and immediately she pulls away. I've been working really hard at being positive, keeping negativity internal and not letting it out. But it's like the moment "old negative behaviours" come out, it's too much and they must be punished. 

Should I expect more support from my partner or is her response to be expected? Have I worn her patience too thin?