I want to improve my English, could you help me?

  Let me introduce myself first. My name is Tiki. I am just an ordinary Chinese student. I'm interested in drawing and writing, my major is art, and I also write novels in my spare time. I think I am working on my dreams so I am always happy!
Today is the start of my summer vacation and I will just stay at home all day. While I had promised myself that I will become a better person over this summer vacation, since the weather is so hot in my hometown, I decided to waste my time at home. Just one day though…maybe!
Ah, how do I make this summer cooler? It is just a joke!
My brother always said that I was so quiet, but in fact, I feel that I am just not good at “big things.” How can I explain this? For example, I can read, write, paint, and even eat, in solitude, but I can't speak or play the guitar in front of others. I simply don't have enough courage to do “big things” like that. Understand?
Seriously, I'm really nervous now, because I'm not confident at chatting in English and I'm poor in grammar! I'm afraid to be different, but I'd like to make progress rather than be different, so if I make mistakes, please help me by pointing it out and correcting it.
Thank you very much for reading my / this essay.

 Good job! I think that you are doing fine! And, contrary to your belief, I think that you are an extraordinary person for having the courage to reach out as you have done. I’m sure that you’ll make many new friends here on iTalki. As to the writing, you express yourself well. I understood almost  everything, every idea, that you wanted to tell me. You should, however, read in English to improve your vocabulary and to expose yourself to the usage of grammar and punctuation. It will also lead to better sentence construction. As to mistakes, we all are human and we all make them, so don’t be so self-conscious about them. They will happen, and you will learn from them; it is part of the process. Your fear of doing things in public, of being judged by others, is very natural. The more that you do it, however, the easier it becomes, so just continue to proceed at your own pace and within your own comfort zone. I did not know if you meant “introverted” instead of “quiet,” so I left it as it was. Similarly, I left "different" alone since I did not know exactly what you were trying to say. I hope this helps you. J.

I want to improve my English,could you help me?

I want to improve my English,could you help me?