In addition to the corrections others have made:

Why can't I speak English fluently?

I have got a kind of a hole in my head, I guess. But guys, now I have a new job, and I have to make presentations in English.  I must improve ...

I want to write here every day, even if I am drunk, even if my cat dies (it will live forever!!!!).

So, check me, please!

Please read the following page, and especially the first post by "Mike", about when you should, and shouldn't, use the word "will" after the word "if":

http://www.efl.ru/forum/threads/33070/

Hi world

I just lost my passion. Why can't I speak english fluently? I am 26 years old. I have been studying English for 20 years! Twenty! I have a hole in my head, I guess. But guys, now I have a new job and I and I have to make presentations in English. I must improve my comprehension as soon as I can. I want to write here every day, even if I am drunk, even if my cat will die. So, check me, please!

Good luck!