This is my first note.

I have just been recommended to use this website from my friend for studying English. "You" havent been recommended, this website has, so you could say something like..."This website was just recommended to me by a friend, for the purpose of studying English."
In addition, As well as, for having for the purpose of meeting friends from other countries.

It is now time (Time is not necessary to say) 2:34AM in Korea.
I have had insomnia since last weak, (correct spelling is "week")

Because I have lots of worries for my future. This is not a complete sentence...You should add this to the sentence above to have a complete thought. For example: "I have had insomnia since last week, Because I have lots of worries for my future."

I do not have enough time to be a student anymore.
It Which means that I should get a job, but I want to get the a job a different way, not as "using"? my major which i have stuydied.(not quite sure what you mean here :)

So, I am just thinking about investment investing for one year more to prepare to get the job.

It is my thinking which i have thought so far tonight! A little awkardly worded...you could say "That is as far as my thinking has gone tonight." Or "That is where my thoughts are at tonight." Or "That is as far as I have thought tonight."

Do i have too much many worries? 

Good job....keep up the good work! :)