You need to know that appetite spurts are a common, normal part of breastfeeding-they represent the law of supply and demand in action. If your baby suddenly is hungry more often, you just nurse more often to readjust your milk supply to your baby's demand for food. Instead of being caught off guard by these inevitable frequency days, expect them to happen periodically and be prepared to cut back temporarily on your other activities and to increase your nursing to stimulate more milk production.
You may have to feed every two hours or so for a couple of days until your milk supply increases and your baby resumes his former schedule. We tend to talk about growth spurts as if the baby suddenly changed his rate of growth or his nutritional needs. In some cases, I suspect that a mother's change in activities may have decreased her milk supply from its previous level, leaving her baby hungry. No matter what has triggered an appetite spurt, your response is the same: stay home as much as you can with your baby for a few days, nurse as often as necessary, drink extra fluids, get extra rest, and don't let your confidence get shaken!