To rebuild your self-esteem you must find your self value not in others. Build your house on sand and you will fail, so to speak. So how do you readjust the way you see yourself? This might be a good place to start:
Self-esteem: Take steps to feel better about yourself - Mayo Clinic
When you start to rebuild your self-image, you begin to see other people differently - not as the impervious emotional and social juggernauts you used to feel they were. It's all a process of readjusting your thinking, getting our of old habits. Another area you might be interested to review is body language. How you project yourself makes a very big difference to how you are received. This has been by far the biggest change in my own life. Often people bemoan that people ignore them because of how they look etc, I can attest to the fact that a very aesthetically challenged individual - such as myself - can transform their interactions by adjusting the energy they project alone! I don't know specifically what things you are struggling with, so I'm not entirely sure what to suggest, but something that does turn up alot is not asking enough questions. That may be something for you, I don't know. If so, let me know and I can arm you with some tools.
When going over these things, drill them hard. Go through scenarious in your head over and over enacting these changes, look for opportunities to implement them. Take note of things that went wrong: Did your body language close up? Did you go blank because you didn't know what to say? Were you gripped by anxiety and too flustered? Knowing what went wrong in a certain situation will help you in future if you use it as a learning tool. It's okay to make mistakes. So called socialites make faux pas all the time. I am astounded how the most social and extrovert people make so many mistakes and how little they are able to read people. It illustrates perfectly that you don't have to be perfect, you don't have to be the most intelligent, creative, talented, "attractive", funny person to have a fulfilling social life. Imagine trying to ride a bike but you slam the brakes every time you feel the slightest bump: you'd get nowhere! That's what SA is like sometimes, if you allow it. You cannot get rid of those bumps, but you don't have to. It's all part of the journey and a change of perspective can make it an enjoyable and memorable one.