Welcome to HealthCareMagic. My name is Doctor Saleem Ur Rehman and I will answer your question.
If you want to understand your condition and its treatment, it is important that you first understand the distribution of fluids in the body.
All fluid in your body is distributed into two major compartments: Intracellular compartment (the fluid inside your cells) and Extracellular (the fluid outside your cells). Extracellular compartment is further divided into Intravascular (fluid inside your blood vessels) and Extravascular (fluid outside your blood vessels). The Extracellular Extravascular fluid bathes the cells in nutrients derived from the Intravascular compartment, and takes the toxins derived from the cells through special channels called lymphatic channels to Intravascular Compartment.
In Short your fluid flows from Intravascular Compartment to Extravascular Compartment at the level of Capillaries (the smallest possible vessels) and from Extravascular Compartment to either Intracellular compartment through the cell membrane, or through the lymphatic channels to Intravascular Compartment.
In your case, the lymphatic channels suffered blockage due to infection and resultant destruction due to formation of scar tissue. You were given
aldactone to increase the excretion of fluids through the kidneys. In this way the vessels were underfilled leading to some degree of "back flow" of fluids from extracellular compartment to the Intravascular compartment.
The exercises were meant to open the lymphatic vessels and to cause break down of internal scarring in your leg (caused by the leakage of
proteins from the intravascular compartment into the extravascular compartment. These proteins are usually washed away promptly by the lymphatic flow. But since the lymphatics are blocked, they have deposited are formed small mini-compartments in your extravascular compartment thus trapping the fluid)
Right now, you will need patience to go with the regular exercises becaues restoring your leg to normal will take some time and hard work. Medicines wont help much and would rather cause harm, because whatever you take will effect all of your body, not just the affected leg.