作文留给更专业的人来改，我只想指出一点是，和中文不一样，英语中如果是两句话之间没有连接词，是绝对不能用逗号的。不能像中文一样一逗到底最后来个句号。比如你第一个逗号两侧就是没有关系的两句话，应该用句号。有时两句话之间有点联系，但是没有连接词，可以用分号。

Tomorrow isThe Middle Autumn Festival in China

Tomorrow is the Middle Autumn festival.  Everyone seems happy around me,but I am not so happy sad because I am far away from my family now.  My friends are busy, I have to be (so I will be/ so I am: Either one of those would work) alone .I feel that if your loved people couldn't be with you ,you can't find someone to share your happiess or sadness,(I think that if the people you love can't be with you, you can't share your happiness or sadness.)  It will be a little lonely!