Sunburn PLEEEASE help?!?

okk so its the day before my graduation & we just had our 'graduation practice' where we sit out in the hot sun for 2 hours. i have VERY fair skin & i forgot to wear sunscreen today. i was wearing a tank top. so basically, i now have EXTREME red sunburns all over my body, and in between them are white markss where the shirt was covering. if you have ANY POSSIBLE IDEAS of hwo to get the redness to go down, then PLEEEEEEEEEEASE tell me. my graduation is tomorrow, and i dont want to look like a red/white streaky lobster! k thanks, best answer WILL be rewarded ;]