Dont water as often. Let the soil dry out COMPLETELY - test this by prodding yer finger in gently about 1-2 inches. If its about 70/80% dry, then water again FROM THE TOP until you start getting a moderate runoff. Let the plants sit for 5 minutes so all the water drains through, then chuck the runoff water outside.
The droopiness is caused by the roots not getting enough oxygen. Could also be caused by ferts, but normally you start seeing blemishes on the leaves. Dont worry about a couple of small yellow spots, but if more than 20% of the plant starts turning yellow, then immediately flush the plants. You do this by using PLAIN - no ferts (bottled is best, dont get mineral water) water, and using 3 gallons of water per 1 gallon of pot. This is a general rule though, you wanna carry on pouring water through until it runs 100% clear. This gets rid of all the nutes. It will take a while for the soil to dry, but when it does, water again with a VERY weak nute solution. The soil is now totally nuteless because of the flushing so youll want to add some. Start with a quarter of what it says on the packet, that should be fine. They still may not survive IF this happens though, it depends how long you let the problem last.