My foot is numb!?!?!?

so on Saturday i dropped a sledge hammer on my foot i went to the doctors and they told me it was just severely bruised. This morning when i woke up my foot was like a numb tingling feeling like when your foot falls asleep i thought that's what it was my foot was just asleep but ive been up now for two hours and i can barely walk on it?! What could it be?