Gardening question about tomatoes?

I live in Florida...It is oven roasting hot!!! my tomato plants are not doing wonderfully well. First they got hit with some bugs, I sprayed but the leaves have turned brown and fell off. They seem to be doing better that way now. The tomato size is small and they just don't seem to want to produce. Any ideas? The soil I have them in is very rich, imported from the garden center.