Trying to grow tomatoes in SC

I have gone from tomato plants in a raised bed with fertilizer and soil from a nursery (planting in various locations) to placing tomato plants in different size pots - yet they all continue to die off or are terribly diseased. I am beginning to think that the heat is so intense in SC (regardless of how much watering I do), that it is simply too much for tomatoes. I have tried all varieties, including disease resistent, mature plants and have purchased them from a variety of sellers.

Is anyone in this region (I think it is 9), experiencing similar problems??

On the other hand, Egg Plant is thriving like a wildfire out of control. So are the squash and certain peppers. especially the sweet italian banana types. Squash does fairly well also.

I would appreciate comments regarding the tomatoes. Maybe I am just doing something wrong but NEVER had this problem up North.

Thanks.