How exactly do people die from electric shock? Also, should i be dead?

WHAT I DO KNOW•I know that as little as 40 or so volts or .1 milliamp can be lethal if it comes in contact with the heart.•I know that electrical currents kill people by potentially two methods: Burns from the heat and heart failure from the current itself.•I know that additionally, high levels of current can cause muscles to lock up, often causing an inability to let go of what is shocking you. WHAT I DON'T KNOW•So far, nothing I have searched up explains the association between length of exposure and lethality, nor the association between body type/build and lethality.•I do not understand the association between volts/amps and lethality. Sources seem to be always in conflict or simply too vague when it comes to what effect these things do and do not have.•The sources I find all point to the heart as the main cause of complications. But none address how the electrical current effects the brain. I find this odd since the brain has a lot to do with the body's electrical current. I assume the current wouldn't often make contact with the brain since it goes down to the ground directly. But if you were standing on your head or something, would that cause electrical damage to the brain? CONTEXTRight, so. This line of thought started because of an incident when I worked at Subway. You know those Toaster Ovens that cook your sandwiches? Well it was broken and we needed a new one. I was asked to unplug the beast, which I did manage to do; but not until after touching my finger directly on the active plug still partway in the wall, recoiling backwards, yelling a distorted "F*CK" in front of customers, and spending the rest of the shift on an adrenaline high.Upon telling my boss about it afterwards, he gave me a hilariously confused look and said I should probably be dead. But he's probably not a good source. THE ACTUAL QUESTIONSIf It helps, I looked up the details on those toaster ovens, this specific type had the following electrical stats:Voltage: 208/240Amps: 30 And thus, my specific questions are:How much of an effect do volts/amps have on the lethality of electric currents?How much of an effect does the duration of direct contact with an active source have on lethality?Does weight or body build play any significant role in your tolerance for electric shock?If the electrical currents were to somehow go through the brain, would this cause damage?Given my account of my experience with being zapped, on a scale of 1 to 10 (10 being Bruce Banner), how dead should I be after that?