Got figure out the trick. I connected the LM35's Vout to AN0 then the Gnd just above the diode to AN1. Then subtracted the two to get the actual temperature. I've manage to measure up to -18C since at that temperature, Fahrenheit would be equal to 0.
Now, the problem lies with using the correct transistor. I'm now having common anode for the project, question is, how will I know what transistor is suitable? For now, Im using 2N3906. it won't work in proteus. I tried actual testing, it won't work also.