Mkjuk, I hope you have loved ones around who can wait on you hand and foot. Or maybe you can rent some?
Minimizing movement is the biggie, and usually the toughest to do. Find comfortable seating positions - usually with cushion support - that won't unduly stress your midsection (easier said than done, granted). Make sure you're properly supported in bed; use as many pillows as will help make you comfortable and breathing easy. The first weeks are the hardest, but it will get better.
And respect the pain! With the deep breathing, in the beginning it will be uncomfortable but it shouldn't be painful. Don't breathe past the pain.
I was never given any dietary restrictions. Maybe just don't put anything in that will cause a strain coming out!