I know what you are describing. It's frustrating to not be the way we know we can be, to be more unhappy and unsure than we would ever like to be.

I second Open Eyes' suggestion about therapy. One way that talking about my traumas and the PTSD has helped me socially is that I am more compassionate with myself. So, when I do not behave as I think I "should," I don't get so down on myself. I cut myself a break. and the end result is, I have fewer times like that. Being understood by someone else has helped me understand and be myself more. I am not sure if that makes sense.

I suspect one reason you worry what others think of you now is because during your abusive relationship, it mattered VERY much what that person thought of you. It was crucial that you be "good"--so your worrying now is a leftover of that. A survival system that served you well, because you are here, a survivor who made it through. Knowing why we do things, how it's connected to the trauma, can help, too.