Although the most appealing thing right now will be to stay in bed and wollow in pain, this is only going to make you feel worse. You brought this upon yourself so feeling sorry for yourself ain't gonna work. Instead get out of bed, go and do something and you'll feel all the better for it I promise.
Eat something but eat something very plain like toast or pasta. Don't eat anything sweet trust me from first hand experience it ain't pretty.
Drinking water is one of them things that is really good practice to do anyway but after drinking alcohol your body is so dehydrated. You owe it to yourself so just do it.
Go outside, the fresh air might help you "clear your head" so to speak. Don't go crazy or anything a quick walk is enough.
Do things to distract yourself. If you "forget" you have a hangover then in theory you shouldn't feel as bad. Start a creative project or watch a dvd just do anything that's going to stop you from moaning about how you drunk too much and that "you'll never go out again" because we all know it's lies.
Take paracetamol. It'll get rid of that pounding headache for one thing and also might trick you into feeling instantly better.
Accept it- after all it was you who brought this on yourself so man up and take it. I would also advise not planning anything for the day after a big night out. In my experience I either end up cancelling or going but having a bad time.
And if all that fails then you should just get back on it. (Warning this may lead to an even worse hangover the next day)
Until next time