Where, exactly, does it hurt?  Bottom, top, specific toes, behind/between specific toes, ball of the foot?  I can't think of any common forefoot injuries that would wait 8 miles to start hurting. Also, overpronating, by itself, is unlikely to be the cause.

Len

First of all do not alter your natural gait to compensate for you injury!  What happens if you do that is you will get another injury from over compensating.  If it hurts that much you should not be running on it.

I can only guess what you have, possibly bursitis or metatarsalgia.  You can read about them here:

http://www.foot-pain-explained.com/bursitis.html

http://www.foot-pain-explained.com/metatarsalgia.html

You should definitely be icing your foot.  You may need a foot pad.

James

quick question are you suppose to wear your inserts when you run? i only wear mine everytime i don't run. ofcourse im running less than 8 miles and don't have any pain, but want to know what i should be doing.