You try to use this Hall sensor on wrong way, this is "only" magnetic flux Hall sensor. These ratiometric Hall-effect sensor ICs provide a voltage output that is proportional to the applied magnetic field. Circuit current should not pass through this sensor, this sensor is for measuring magnetic flux with ferrite core. Probably you kill like rabbit that Hall what you try to use, get another.
There is other type of Hall sensors where current pass throught Hall sensors. You can see ACS712 serie of Hall sensor, this sensor is used on similar way what you try.
;-)