too hot.

so i gave up studying, and came back home early. bBut i regret my decision, because the library is colder than my house.

"..." Is very informal, just remember that. In formal English, you can't start a sentence with words like But, And, Because, etc. But in informal spoken english we do it all the time. :)

because library is colder than my house.

See how I corrected above. It should be part of that sentence.

i just want to stay with ice water, lying in my bad.

Ice water is two words.

i think the earth gets angry because of the man.

When you use "the" it sound like you are talking about ONE man. Using "man" or "men" here without "the", shows that you are talking about ALL of the people in the world.

I think today is the hottest day in this summer.

You always have to capitalize 'I'.

i just want to stay with icewater, lying in my bad bed.(The expression "stay with ice water" doesn't make sense.) Better to say "I just want to drink ice water and lie in my bed"

i I think the earth Earth gets is angry because of the man.(This sentence makes more sense if you use "man" to describe all humans. And use "the Earth" because it's the name of the planet) But better to say: "I think the Earth is angry because of humans." Or "I think the Earth is angry because of what humans have done.")

please Please calm down and cool me down.