I was trying to fall asleep, (przed 'but' potrzebujemy przecinek) but the sound of the howling wind kept me up. I 'was' (zle slowo - 'came' jest lepiej) all over in shivers.
'It' THIS had all happened 7 days 'before' (jak dajesz 'before' to musisz napisac before what? tutaj daj 'previously') and I knew THAT I 'never I' (niepotr) would NEVER forget it, because it was the scariest day of my life.
The morning sun was blazing when 'i' (dlaczego dajesz 'i' mala litera? Co to?) woke up. Next 'i' (popraw) strolled to the kitchen to have breakfast. Suddenly I heard a doorbell and I rushed to open the doors because I had been expecting a package 'from the internet' (to jest nieprawda. packages come from FIRMS which you find on the internet).
You are the ancestor of 'the' (niepotr) Poseidon and you have to 'go' COME with me!" Suddenly, a big portal opened and I yelled: "I 'didn't' HAVEN'T 'feed' FED my dog!"
He told me that only 'me' (zle slowo tutaj 'I') can rescue the world, because Hades had 'had' (niepotr) opened the connection between the real world and the ancient one.
The wind was howling and suddenly (daj tutaj...with MY own eyes) I saw
Cerberus - the three-headed hell hound which was a defender of Hades
Gates - 'with mine own eyes' (niepotr). He attacked me and bit me extremely
'seriously' HARD. I hissed: "It's over", but unexpectadly, he stopped 'stopped' (niepotr) and I passed out.
I didn't know what IT 'all this' (niwpotr) 'were' (tutaj WAS) ALL about. Since that day I HAVE had the same nightmare every night. I tried to forget about it during the next FEW days and I came back to normal life.
I went to 'a' (po co to? niepotr) bed and tried to fall asleep.