Congrats on your surgery and your great recovery. Walking and fluids are really key not only in the beginning, but throughout your journey. When I had surgery, I had trouble slowly walking for 5 minutes, but by walking several short walks every day, I can now walk, run and hike for hours. Also making sure that you get enough fluids keeps your body healthy. It may be hard at first and you may have to experiment with different things that settle and taste better, but keep it up. You can do it! For the first few months, I focused on herbal tea and SF popsicles because I had trouble drinking plain water.
Keep us posted on your progress!