Not to make this about me (always a great temptation, that) but very briefly: I didn't last decades with the pain. I've only lived with it for the last eight months or so. At the time, my mind pre-empted it without my conscious volition; I went about my business, but at an enormous hidden cost. I didn't grieve and was numb about the whole thing until it suddenly sprang on me thirty years later. I knew roughly what BPD was but had no idea that I'd lived a lifetime with it until I started researching. Maybe there's a kind of unconscious courage in your mind's allowing you to feel your emotions in a timely fashion; that may sound like the cold comfort of all time, but you are getting help, you're here talking about it, and that is so much braver than burying it.