Hi Meili
So, I'm curious, how many others experienced this?
to some extent.
I had become a spineless, snivoling, whiny, angry, idiot because I had lost all of my self-confidence (well, what little there was to begin with, but that's a different discussion).
It seems painful to have that feeling as if you're losing your self-confidence. I can relate. Even without my ex I could be more self-conscious than self-confident.
Also, I'm reading a sense of pain from self-judgments in this post. Let it out--you're most welcome here.
In the long term, do consider having a look over
mindfulness Meili. I think this is a good place to start if you're seeking to improve your self-confidence. You ideally want to look at your self-criticisms again as part of
Acknowledgement (I'm taking a guess, my apologies if I missed) when you are in a state of wise-mind. You'll find you can access forgiveness and an absence of inaccurate self-judgment, depending on where your self is at in that point of time. It's applicable even after separation.

An example of what this can do is allow you to see things clearer. Instead of snivelling, its also indeed an accurate communication to say you are displaying a "tearful behaviour" to get what you seem to think you want. You can see it accurately communicates your feelings but it does things to take the edge off. Healing gets easier to do.
I hope you get some rest from the residual negative feelings.