My Gran died today :'( :( >> in middle of exams >> please helpp :'(?

My gran died today and she was 90 years old and she was like my best friend. i love her so much and i dont know how im gonna be able to cope without her and then to make it all worse this has happenned right in the middle of my gcses :( i have a maths gcse on monday btu i just cant focus and work and i haven't stopped crying since i was told 4 hours ago :( i dont know what to do and i just feel so hopeless and i know i need to be strong to help my family through this but i just cant find the strength and i dont know how to :( and to make it all worse my parents want to organise the funeral for my last day of school and i feel really selfish saying this but i dont want to miss my last day of school and seeing all my friends for the last time to go to a funeral and i feel so bad just saying that and i loved her so much but i just dont want to have to say good bye :( please help me because right now i feel so useless and i just dont know what to do and how to cope :(:(