The first few days of your Quit can seem to be some form of punishment, it's not. Addiction is a beast, it finds it difficult to let you go, but it will. It will if you're willing to stay calm, to remember that you're an addict, and, last but not least, to remember why you quit.
Remember to be grateful for each and every little step in your recovery - that's an important tool. And, most of all NEEGU (never, ever, ever, give up).