pain on outside of left foot

i went on vacation for a couple of days and was on my feet for practically the entire time.
the next day (after my vacation) I was at a wedding rehearsal when I experienced a very sharp pain on the outside of my left foot.
i couldn’t walk normally, but if I “tip-toed” my foot didn’t hurt.
i’ve stayed off of it for a good while and there was no more pain.
i went running the other day and after about a mile, my foot started hurting again, but it is fine if I walk normally.
any ideas of what the problem is and how to fix it?