I don't have BPD, but do self harm. I'm not sure I've ever been invalidated like this. My upbringing was full of love and I was always encouraged to share my emotions. Lots of hugs, kisses, bedtime stories, smiles, laughter... Also, and I guess it might be a bit unusual, but whenever I've been in hospital for mental health reasons, I've had "get well" cards, fruit, flowers etc brought in for me.
With my diagnosis, it's a weird one. I didn't know about it until a doctor who didn't know me let it slip during a mental health act assessment. He'd read it on my notes. I've always been told that my behaviour/thoughts/feelings are due to being unwell. I'm not sure it made me feel validated. I mean, in some ways it's been positive because I can attribute what I'm like to something, but at the same time, it kind of invalidated me. Not in the way that I feel like a fraud, but in the way that I feel as though things I think/feel are not real - they're all part of an illness. That's not the case, even though I'm told it is. That can be equally as invalidating, if that makes sense?