Today

Today everythings is has been bad for me.In the morning,I got up at 6:00.And then I go went to the park to read English,everything is was normal.But when I finished reading., I dicided decided going to go home to get something left I forgot,but I forgot the most important thing,I left keys on my desk.At that moment I feeled I just felt like a ass,no no no not like ,it's the truth.UM.....I was such disappoint so disappointed about in myself.Why do I always do in error things wrong.
Next, when I arrived in at the company,I found that so many things were waiting for me to deal with.This is was not too bad, at in the afternoon I had to work with somebody that he is who was a disgusting man in mind (this doesn't translate well, maybe say "a perverted man").But I have no choice, so for work I must stand on him.
I thought, when the time's (contraction of "time" and "is"; requires an apostrophe) over up and I come get off work,I can do something enjoyable.But I was wrong. when I came to my home,I found I cann't couldn't open the door because I don't didn't have the keys.
It is actually bad day,isn't it?
Damon,Diary.

Hi Damon,

In English writing we always use a space between a comma and the next word. 

Cat, dog, hamster is correct

Cat,dog,hamster is not correct

From reading your text, it seemed that I was correcting your verb tenses much more than the other mistakes. It might help your writing to revise the past simple and past perfect tenses :-)

Today

Today everythings is has gone badly for me.  In the morning, I got up at 6:00am and then I go went to the park to read English. Everything is seemed normal. But when I finished reading. I decided going to go home to get something I had left behind, but I forgot the most important thing, I had left my keys on my desk. At that moment I feeled I just felt like an ass, no no no not like [what are you trying to ay here?], it's the truth. Um.....I was such so disappointed in about myself. Why do I always do in error make mistakes? 

Next When I arrived in company at work, I found that so many things were waiting for me to deal with. This is not wasn't too bad, but at in the afternoon I had to work with somebody that he who is a disgusting man in his mindset. But I had no choice, for work I must stand on him I had to work with him.
I thought when the times over and come off I had finished work, I could do something enjoyable. But I was wrong. when I came to my home, I found I couldn't open the door because I didn't have the keys.
It was actually bad day, wasn't it?
Damon, Diary.