Why so insecure?

Upbringing. That's pretty much always the answer for this kind of thing. People learn what to expect from the world in their formative years. If they are taught by their community to expect pain, they will expect pain, and from there it's just a question of their coping style, which is usually also taught to them. (Screaming, violence, substance dependency, etc.)

Men are like this, too, Anon.

I'm not a woman but will speak on what little I know from life experience.

From a woman's perspective, an offer to share intimacy is not necessarily validating in the way a similar offer may be received by a man.

For some, perhaps many, women there is the looming question of whether an offer of intimacy is simply a man looking to make them the object of their sexual gratification. Many women are not interested in that.

As men, we're not used to getting offers. So much so that when we get one it makes our day, week, month etc. For many women, the challenge is not getting offers, but there is a looming question of whether the offer genuine. What is the intention of the person showing interest? It's not that men aren't also concerned with these questions. It's just that, for a variety of reasons, the stakes are lower for men. So they spend less time thinking about them and more on just being excited someone noticed them.

Maybe she destroyed her own sence of self worth like me, but then again I did it to keep my ego in check so probably not. Can't really get more unearned ego that a California-Scot with anger issues and a dual superiority-inferiority complex.

Imma guess this hits about 95%.