Help im in the musical and lost my voice?

ok soo a couple of days ago i got a little cold and my thorat was a little scratchy but yesterday i came to school and my voice was cracking and cutting off and getting higher pitched with every word i said and it wasn't just like the puberty squeaks. anyway my throat doesn't hurt but i cant sing at all and i can only talk in a low octave so i sound monotone. pleas help the musical is in march and i need to be able to sing !