Don't know what more to tell you, except that you definitely need to water every day unless it rains - not just a sprinkle, either. Deep watering or heavy rain. Tomatoes have roots that go downwards a long way. If you're just wetting the surface, they're not getting enough.
I would definitely try a boost of soluble fert, something like fish emulsion is good or a specific soluble fert for tomatoes. I've also been using alfalfa pellets as an amendment on all my plants for a while. You can buy a 50lb. bag at the feed store for about $20. Anything that needs a shot, I make alfalfa porridge by putting a couple of cups of pellets in my watering can (I have one without a strainer on the spout) let it sit for a couple of hours, stir it up and pour it on the plants.
Last year we also had a bed at our school garden that we had filled with some really lousy topsoil. The plants were not growing well or looking healthy, but we had two bags of worm castings donated to us, and I spread half a bag around those plants and watered it in. Boy, did they take off!
