Thanks for writing to us.
The immense pain in the toe along with the color changes are likely to be due to infection in the area. A stress fracture
is less likely since you are habituated to walking for long distances. A direct examination will confirm the diagnosis.
I hope this information has been both informative and helpful for you. You can consult me again directly through my profile URL http://bit.ly/Dr-Praveen-Tayal
Dr. Praveen Tayal