I dont know what hit me but I cant feel my leg anymore, all I can see is a tangled mess of muscle bo

I dont know what hit me but I cant feel my leg anymore, all I can see is a tangled mess of muscle bone and blood my body is screaming for the agony to end the only thing I have is this blue device on my chest. I was told by the trader I bought it from that it should only be used in emergencies. The pain is not unbearable anymore, but the light is blinking now. I dont know how long I have left. will the darkness return when this thing runs out? I dont want to fade away...