[TomatoDon]

You probably have a combination of things going on here. Some might consider it a bit amazing that the plants have done as well as they have.

In my view a five gallon container is an absolute minimum for tomatoes. My personal preference is 20 gallon and above. I'm guessing that with the heat of this summer the soil temps in those containers are much higher than in the natural ground and are having a big effect on production and overall health of the plant.

Fertilizing every week would be another potential source of trouble. Don't love em and feed em to death.

So...You've got small containers, a very hot summer, and an over dose of fertilizer all working together at the same time. Try this. Build an Earth-Tainer per Raybo's instructions and transplant the tomato and all five gallons of soil into that. Add new soil mix and water it all very well to dilute all of this fertilizer you've been using. Keep the soil moist, and if you have hot direct sun on the container try putting burlap or even a light colored towel around it to help insulate and deflect some of that direct heat from the soil and root zone. Give this a chance for 30 days and see how it works. I'm guessing you will see a huge improvement.