ankle pain while exercising

I have never really been a walker, I like to bike, swim or inline skate.
About a month ago I began walking with my husband.
Both my legs right around my ankles begin to hurt severely, mostly on the outer aspect of my legs.
They burn and making my ankles feel as though they are about to give out.
If I keep going after about a mile and a half the pain begins to subside.
But for that first mile and a half I am in agony.
The pain usually only presents when exercising, but today after exercising yesterday they are both extremely sore.
I have high arches, I don’t know if that means anything.
I watch everyone else walk and it looks so relaxing, why can’t I experience the same.
Could you please give me some advice.