A weird day

Today was a very strange day.
In the At morning I fought with my colleague. That was horrible, I hate that guy! I spent a long time to helping him and lobbying people that he is a good one but he was thankless.
I felt sad :(
after half an hour my friends called me because they wanted to hang hung out. It was good to see them after such a this long while.
We went out and then thin It started raining. That was funny!
I feel better now :)

Well done, it is well written and easy to understand there was only a few small mistakes.  However the punctuation needs some work.

There is no space between the last letter of a word and a punctuation mark .,?! But there is a space after them.

"Today was a very strange day. In the morning"

After . or ! or ? The next letter is capitalized because these end the sentance.

, or : or ; do not end sentances so the next letter is not capitalized unless it is a word that is always capitalized such as I or English.

You also use ! to end most of your sentances.  You can use ! to add emotion, strong feeling or when someone is shouting.  

Also forexclamations like Hi!, Ouch!

"I hate that guy!" and "That was funny!" are good examples.

...he was thankless! - a '.' would be better here.

Hope this hepls

A weird day

Today was a very strange day ..
At morning I fought with my colleague .. that was horrible, I hate that guy ! , I spent long time helping him and  persuading(lobbying) people that he is a good one but he was ungrateful/thankless/so selfish !
I felt sad :(
after half an hour my friends called me because they wanted to hang (hung) out , It was good to see them after a(this) long while .
We went out and then It started raining ! , That was funny !
I feel better now :)

Lobby refers mostly to political group of people promoting their economic agenda not really one person helping the other unleast you have tried to bribe your colleagues:).