i had the same thing mates,plus a fallen instep in the right foot.fookin agony it was!.
eventually,i went to one of those scholl shoe shops & bought some proper inserts for my boots that lifted the instep up to the proper position.it was instant relief,cost a few quid,but the relief made up for it.
you have to buy them as a pair so you have balanced support.
spend a few quid mate,cos youre on your feet all the time.best of luck,fookin good xmas present to yourself!!.