I worked out and now have MAJOR REGRET!!!!!
Have you been walking all along or did you just start out trying to walk 30 minutes?
You need to start slowly.. I'm a walker (I have walked the breast cancer 3 day for the last 10 years) and I had to start out slowly.
I would do only 5 or 10 minutes at 1.2 mph..3 times a day. I worked myself up to an hour at 3 mph but it took me a few months to get there.
I would rest a couple days and try again when you are not in pain but only do 5 or 10 mins at a low speed... if that goes well try walking another 5 mins a few hours later. Work yourself up slowly...
How fast were you going? Walking on an incline or flat?
If you're hurting, wait until you feel better to get back to exercising. Pain is your body's way of telling you that it doesn't like something you're doing. Listen to your body so you can heal quicker; then you can really kick some ass :)
Feel better!
But I wanted to ease myself into it as It just wasn't worth it to me to injure myself early on and end up having to be half-arsed about it for months because I was nursing an injury.
Think about this life change as a marathon rather than a sprint. You have to pace yourself at the start