For me it was when I got together with my (current) SO about eight years ago. I realized there are feelings in my chest that are not normal to feel all the time, especially if there isn't a real reason to feel these kind of things. (Like, mostly anxiety and overthinking all the time, but also self hatred that occurs when my bpd kicks in and makes me hate myself for my bpd which causes the bpd - I like to refer to it as the demon in me - to be even more present. Like a vicious circle. ) 

Like, I  first met the 'demon' long time ago but it didn't ever have a name or face, which was scary. I just knew something in me wasn't right. Does anybody else feel like this? I almost felt kind of relieved after i got diagnosed. I know my demon now and that's my only chance to (successfully?) fight it.