My feet hurt when walking and unable to stand too long

I have problem with my feet. I don't know whether it's due to diabetes or a common foot problem or skin problem. Someone said it's because the germ in water. Now my feet hurt when walking, unable to stand too long. The skin on my feet turned black. I post the picture in flickr
http://www.flickr.com/photos/77270117@N02/7493024900/in/photostream

I hope you can help me


Any help would be great, thanks a lot
Regards

Maybe Plantar Fasciitis. It is really painful. Maybe see a podiatrist for a proper diagnosis and treatment if you can afford and it is really sore.