Doing talks in school

I have to do a talk tomorrow in school and I know to some people this will seem a stupid thing to get worked up about.

but I am terrified. I cannot do this talk. Im not just a little nervous..I literally, physically cannot do it because of utter fear. I do not speak in school as it is and everyone knows im like that but it seems to have got worse.and so I know I will not be able to do this talk. I mean even when I speak to some teachers I totally loose my voice..

I told my teacher I couldnt do it and she was just like oh your be fine..and I spoke to my friends and there just like you can do it stop being stupid..but I dont mean to sound childish or nothing.

:’(

I dunno what to do.. I could skive that lesson but then I will get called down to the office and my mum will be phoned saying im not in class.. Or I could go to class and tell her I cant do it but then the whole class will thinkim being pathetic..or I could try and do it but I know I will not be able to say anything and will end up walking out of class..and everyone will make fun of me and il be made a fool..

HELP…What can I say to my teacher..or what can I do.. :(