I am using fish emulsion to baby a sickly tomato. It seems to be working. I gave all my tomato and pepper plants a feeding. You should be able to find fish emulsion or fertilizer at any nursery. I always use it when I'm transplanting. It may be labeled something like Neptune's Harvest. Water the leaves not just the ground.

Boy that must be frustrating. There are many possible reasons your tomato leaves are curling. Among these are disease, pests, watering, nutrients, virus, stress, herbicide, or temperature.

If you could provide more info, maybe someone with more experience can help. Or you can google "tomato leaves curling" to try to research some of the possibilities and remedies.

There is also a Tomato Pests & Diseases forum here on GardenWeb:
http://forums.gardenweb.com/forums/tompests/

Here is a link that might be useful: GrafixMuse's Garden Spot