Did he numb it before he injected it? If so that medicine depending on the numbing agent should last no low than 12 hours. Put ice on it though those can hurt just from the pokes of the needle.
If it's numb related to the neuroma then it will stay that way until the neuroma gets small enough to open the nerve paths again.
If the numbness is new let the Dr know.
Hope it feels better soon foot pain is like teeth pain awful and no way to get away from it.