I was recently diagnosed with BPD so realising things are starting to make sense has been very liberating but also a bit scary. I’ve been lurking on this sub and it has helped me a lot to come to terms with my own behaviour. 
What I wanted to ask you guys is are you also unable to feel happy for other people? You know how some people feel genuine excitement if their friend gets a new job etc. This just does not exist for me. It’s not that I feel envy or even jealousy, I just don’t care. My closest friend could get the best news ever and I’ll react accordingly to make them feel happy, but in my head I’m just like um whatever it’s not my life, not because I don’t want to but it feels like I am just unable to do it. Maybe I’m just an asshole through and through but this has bothered me for a while.