Help...I've eaten like a pig today!?

No you wont die, just make sure your are exercising right to compensate for all the added calories and staying active. DO NOT! make yourself vomit to get rid of it, that is an eating disorder in the making and will only make it worse. Just make sure you don't keep it up and keep an eye on what and how much you eat. Doing that and exercising, you will be fine.