A/C Blows Warm Air
 

My a/c was blowing warm air. I saw that the compressor clutch wasn't engaging. When I jumped the low pressure switch, the clutch came on, so I rented a pressure gauge manifold from autozone and attempted to add some refrigerant. After starting the car, turning the a/c on, turning the fresh air blower on, and jumping the low pressure switch, I started adding the refrigerant. I added maybe a half a can before noticing the high pressure was at zero (low pressure at about 35 after adding some refrigerant). Anyways, does this mean my compressor is toast, or could it be something else?