What may be more important than the social interaction itself, is how we talk to ourselves after the interaction. It’s very common that as we begin to challenge ourselves, social interactions may not always go as we hope. This is to be expected. Your natural inclination will be to use this “bad experience,” as proof of your social inadequacy. In reality, the attempt to go out of your comfort zone is a win in and of itself. Give yourself credit for pushing yourself and be careful not to fall back to old patterns of criticism (calling self a loser, idiot, etc).
Keep in mind that due to the social anxiety and low self esteem, our view of reality is distorted and biased. Did the interaction actually go as poorly as you thought, or is that just your negativity clouding it? Stick to facts about the interaction rather than feelings or interpretations, as these are completely subjective.
Lastly, even if the interaction objectively went poorly, that’s cool too. Our job is not to be perfect in social situations. Life is full of embarrassing moments. It’s time to give ourselves the permission and grace to embrace and accept our flaws and mistakes. Learn to laugh with ourself, not at ourself.