I think that maybe a different way to look at it would be to ask: why is vulnerability a bad thing? Everyone has emotions. Everyone is impacted and affected by things. To use your situation as an example - your partner betrayed you. You SHOULD be vulnerable to that. The fact that they can’t fathom having that level of vulnerability, to the point that they claimed you were trying to manipulate them, is the problem. That kind of emotional invulnerability is what leads people to do the kinds of things they did.

I truly believe that being vulnerable in front of someone, especially when they have hurt you so much, is strength. Showing someone how much they hurt you is really hard. Find people you can be vulnerable with. They’re out there.