Staying on top of the pain is really important, in my opinion. I don't think this is the time to be reluctant to take pain meds. Your body will tell you when easing up on them is appropriate. You'll feel much more like walking, etc. if you are not in pain. Your reaction to food sounds familiar. Try to stay hydrated above all and eat very small amounts of foods which seem interesting to you. Eat more frequently than you would ordinarily but just eat a bit each time. Most of what works for us is discovered by trial and error. Don't be hard on yourself. You are really at the beginning of this healing process and things will change for you. Keep writing and let us know how you are doing.