I think this whole issue of external validation is interesting, because my own recovery from abusive relationships went like this:
Childhood - hmmm...
Marriage - nearly 20 years of verbal abuse
Next few relationships also abusive, perhaps even more so, in different yet crucially similar ways!
EVENTUAL PENNY DROP MOMENT:
Fuck this, I need to look after myself better...
Then many years alone, increasingly happy because I was learning to look after myself properly... and a very important element of that was not allowing anyone else to spoil things for me, ever again.
I'd love to say I've done all my the necessary healing myself, alone. But essentially my recovery strategy has always been damage limitation. I restrict my interactions with others.
It's only since meeting DH#2 that I've really managed to get the hang of being someone whose feelings and thoughts actually matter. Him constantly demonstrating that they do has been like a gentle learning curve for me over the past decade. I'd like to think I'd have grasped all that without this external validation, but I'm not sure I would. I knew it theoretically of course, but really "getting it" required more than that, for me.
My personal barriers have improved as a result and I am less tolerant of shit that I'd once have accepted as normal, even expected.
The main work we have to do for ourselves is, as @Watchkeys says, to learn to re-parent ourselves: being kind and understanding towards ourselves. No point feeling sorry that no one else "cares" enough... WE must care enough for ourselves, starting now. Once we learn to do that, everything else falls into place.