Looking at your plant and the thickness of the leaves it will drop quite a few leaves as flowering continues. The plant will drain all the energy out of the fan leaves over a period of 2-4 days leaving them yellow and ready to fall off. Leave them on the plant till they are yellow so they give up all of their energy to mama. That said however I do not think the drooping leaves are a product of defoliation. I believe your plant is in full bud production mode and sucking up everything it can for energy. If your 5 gallon pot is light in weight which you indicated it makes sense that your plant is thirsty. Just be sure not to over water it to make up for letting it get too dry. Put a teaspoon of molasses or honey into a 1/2 gallon bottle, PH the water, and slowly pour it into your plants pot. Start at the center going in a circle and slowly move your way towards the outside of the pot. Check the plant in 45 minutes to an hour. I'd bet you a dollar those leaves will be standing back up again. When my plants defoliated themselves the leaves didn't droop. They were fine with the exception of their color which changed to yellow eventually and they'd fall off.