a scary nap dream

In the dream...
I was in my own class {chemistry laboratory} and chatting with my closed friend happily.
In a sudden my aunt which she lives opposite my house neighbours rushed into my class and called me out of the class in a hurry.She telled me that my mom had been died without telling the cause of death and hurried me back home.
When i back home,i saw everyone are preparing and setting up the ceromony.At first i really don't believe to it until i saw my mother lying in the coffin.At that moment i feel lost, a sudden blank and also helpless, because she was the only one parent who take care of me, teach me and give advise me on choosing the way to make my life perfect and there is no one can replace her because my father had past away seens i was in primary 4.My tears flow out just like a fountain, non stop flowing after knowing her death.
After some times, i stop crying and asked a guy i think he is my closed friend which i don't know how he know my mother [think back quite an impossible thing].I asked him what causes my mother to death.He reply me that, my mother died because and accident.That accident is a cart which send a lot of new cars to the show room fell and press to my mother cars{kancil,perodua}and also more than 40 cars on the federal highway.
After knowing it, i continue crying all the time although the ceromony starts.The priest direct the other relatives to sing and also invocation.After that i was pleased to talk something.My feelings really uncontrollable and i force my self to give out everything relevent to her, every sweet moment with her in a speech form [with crying].She is the best mom that i receive from god.In my heart i saying that why god you bring my mom away,at least let her live in this world until i know how to drive.
A sudden again, the dream was break because i wander to go for a pee.At that time i realize that that was just a scarry dream and i have tears on my face and i do scream in whisper form.When i saw my mom is having her nap on the other sofa then only i calm down.This is the worst experience of dream that i ever experience it.I t really feel bad.I dislike it because it was to real.