Hello again Jayden! 

You were right, I was sick for almost 10 days. It was very difficult to get better, but I am well now. Thank you for being kind enough to ask about my health! I hope your studying has in no way suffered for my inability to teach this week. But I am glad to be back. I will continue by correcting the sentences you've written here and we will speak again next class time! 

I suddenly heard that you won't teach me at tomorrow class. [You've done well here, all you need to add is the word "be" between wont and teaching and an "S" onto the end of "tomorrow" so the whole thing would read: "I suddenly heard that you wont be teaching me at tomorrows class"]
I hope that you don't have bad things. [Instead of saying "I hope that you dont have bad things" you would say "I hope bad things havent happened to you." using the word "happened" and selecting "you" as the subject of the sentence.]
So, I'll meet you this Friday. 

In addition, I looked your 2nd feedback. [Just add the word "at" here so it would be "I looked at your feedback."]
There are a lot of grammar's mistakes. 
So I try to be careful to make sentences. [Just add the words "will" and "when I" here to declare what youre going to do "So I will try to be careful when I makes sentences" would be the correct sentence. But youre still doing very well!]

Today, I will talk about my wife and son.
My wife is housekeeper. She is responsible for all household chores.
She especially prepare to my lunch at work. [Instead of she especially, say "Especially, she prepares my lunch for work."
I want to help you. But I am so busy to work so I can't. [instead of "I want to help you" you would say "I want to help her. but I am so busy at  work, so I cant." adding the at as well]

My son is a middle school student.
In Korea, It's very compitetive to enter universities.
So most high and middle school students study until midnight every day.
My son does so. He studies very hard without sleep.
I love my family. I try to hang out with my wife and son much more.

The last paragraph is perfect. You're doing really well on reading and writing, I hope you continue to work hard at your english studying! 

Thank you.
Jayden.