According to the data you provided, you might be experiencing neuropathy of a nerve that was either damaged or pressed when you fell on the wrist. In both cases, visiting a neurologist or traumatologist is highly recommended to determine if damage was done. If no damage is detected, then a possible pressure on the nerve should be removed in order to prevent further nerve damage (loss of sensation and paralysis of the muscles that are controlled by the particular nerve).
Of course, there is also a possibility that the condition is only temporary if the tissue in the wrist is swollen and the symptoms might completely disappear once the bruise is gone.