Swollen legs and feet with pain. Took hydrochlorothiazide, no relief. Soda increases swelling. Soda problem ?

I work and live where there is nothing but cement floors. Recently, I have noticed (again) that my legs and feet are swelling and eventhough I take hydrochlorothiazide , there is no relief. This is causing so much pain in my legs that after 8 hours at work I am miserable. I drink about 2 bottles of caffinated beverages daily and about 2 to 3 bottles of water. I have noticed though, that if my intake of soda increases, my swelling becomes suddenly onset. Is the soda the problem? Please help, as I write this I cannot walk without extreme pain and look like a 90 year old walking.