When I got (cos brak) the door, suddenly I realised that something was wrong. 'Opposit' (ortog) me was standing (cos brak) coffin.
When I regained consciousness I 'watch' (tutaj czas przeszly, no i przeciez masz 'regained' co jest czasem przeszlym) the street looking (cos brak) somebody who could had 'live' (calkowicie zle slowo) the coffin in front of my door, but no one was (tutaj brakuje THERE),=.
There was (s bak) card with (cos brak) message 'It is for you'. I couldn't believed in that, because I 'hadn't' (tutaj sie pogubiles, lepiej napisac w calosci...did not have any) 'enemys' (ortog). I (tutaj brakuje slowa 'quickly) 'fast' (zle slowo) 'run' (zly czas) call to the police. When I put 'off' (zle slowo) the phone I 'hear' (zly czas) approaching footsteps. I turned around and saw (cos brak) man. His face 'seem me familiar' (zla kolejnosc slow...seemed familiar to me). I remembered that he 'is' WAS (cos brak) father (cos brak) the boy whoM I hit at a pedestrian crossing accidentally.
I knew that (kto? co?) must fight with him. I grabbed the first thing that was 'under' (nie, napisz 'near to) my hand.
When he approached me within 2 steps I 'uplifted' (zle, tutaj lifted up) my weapon and hit the man in the head. I didn't know that I 'have' (daj HAD) so much strength.
In a moment 'arrived' (daj to na koncu zdania) the police.
Later it turned out that the man was mentally ill. 'man' (niepotr).