It's reasonable to be hurt by how you were hurt, but always remember: IT'S A PATHOLOGY. A literal personality disorder.
They can't not be like this. It's just how they are. If they were honest, you'd have been able to see the snake they are under the mask, but they're skilled liars and manipulators. You don't think like this, your brain isn't wired to recognize it when it's wrapped in a thick cloak of deception.
You didn't stand a chance.
Evil can be charming, and manipulation can look like generosity.
Its' not your fault, and you're DEFINETLY not alone.