Hello Lyra,
Thank you so much for reaching out to us and sharing your story with us. I am truly sorry that you are going through this difficulty.
Some people are naturally born or grow up to be introverted and shy, and that is totally okay. All types of personality are beautiful, unique, and crucial for diversity and betterment of humankind. But problems come when that "shyness" part becomes incessantly persistent and brings too much frustration, anxiety, and stress over your daily life. From your description, you experience anxiety and fear of judgement and mocking during daily social interaction, you are too anxious sometimes that your language skills are affected. You also experience symptoms such as having mind blanks, being overly self-conscious. These sound very much like the symptoms of social anxiety, but I am not the expert to tell you what exactly you are experiencing. However if you truly want to improve your circumstance, you should talk to a therapist/psychologist and see what her/his opinions are and what to do to make you feel better in daily social interactions.
I highly suggest you talk about this in detail with trusted adults, then try to seek professional help. If you find organizing your words and expressing them orally in front of people difficult, you could write a well-organized and detailed letter and hand it to them. During your daily activities, you could try to stop worrying about others’ thoughts about you and start to focus more on things at hand, and there is no way you can change how others think about you and mere thoughts cannot hurt you unless they turn into action or words, but that’s a different case. I know it’s going to be hard, but try to be easy on yourself. It’s okay to make mistakes. It is okay to be different. It is okay to not do everything perfectly. The important thing is that you get to experience this world in your unique way and enjoy your life without constantly worrying about how others think about you.
A book helped me tremendously at that time and it is called "The Subtle Art of Not Giving a F*ck: A Counterintuitive Approach to Living a Good Life”. It is basically about not giving a fuck to what other has to think about you because everyone is essentially busy with their own business. Usually, a huge mistake in your eyes might be just a background scene in others’ mind on which they will spend 0.001s , and they will spend the whole day thinking about what’s for dinner.
I really hope your situation improves and you could always
PM me if you want to chat.