Pat, welcome to our forum....great place, isn't it. My advice, like so many others, may be to slow down a bit on your walking or do it slowly many times a day. I'm six months out of surgery now but at about 7-8 weeks I felt like walking a little over a mile twice a day and it came back to bite me a bit. Nothing serious, just got so fatigued by end of day. Cut it back to a mile once a day and felt alot better. Our brains may be very enthusiastic but our bodies sometimes have different ideas.
Glad to have you here.
Midge