I often feel this way on the inside, when I am by myself. Maybe my advice will be "cringe" or not very useful. Actually, the thing that helps me to not feel like I lost something is to take that feeling that everything is shaped by this flaw and to also think that the good things about you would maybe not be there if your entire life had this different trajectory because you were fluent and not socially anxious. I don't know actually how old you are but this is only something I can say or do now because I am older. I never felt like I had a personality before or even much like a person, like everything was just anxiety and life was a long list of things I was too scared to do. Over time, even when you are shy, you realise that other people see a value in you and you have your own strengths in yourself that you value. Like for me, I am very shy and anxious and maybe I am not very good at speaking but, if these things were fixed, I wouldn't have grown to become so hard-working and thoughtful, I wouldn't be so calm and level-headed, I wouldn't have become so observant, I wouldn't have developed my inward-facing interests, and I would subsequently lack many of the things I have experienced and the people I have met. I feel satisfied to just be a boring type of person in even my own life or like it's okay to be flawed. I used to feel like everybody else was perfect but now I don't have this feeling. Sorry, this is likely not very useful.