Motor doesn't run.

I started up my car this morning to go to class and it wouldn't. The starter turned over fine, I seemed to have full battery, but it wouldn't start the motor. I noticed with the ignition on it said I had absolutely no gas. This confused me, I knew I was low, but not completely empty. However, pressed for time, I took another car with a gas can and put about 3 gallons in my car.

Still didn't start. Fuel meter jumped up, though. It puttered once, and once again later, but never started. All of a sudden all the electrical went dead in the car, but I found it to be a loose negative cable.

I read the codes after class and came up with the following:

P1233 "Manufacturer controlled fuel and air metering"
P0109 "Fuel rail pressure circuit malfunction"

A search here on the forums comes up with

"P0109 MAP/BP Circuit Intermittent "
"P1233 Fuel Pump Driver Module off-line."

I'm going to go look at it again, but does anybody know anything about any of this? I'm sad.

Where's that switch?

Edit: The interior coverings in my truck are removed for wiring and grounding for my sub and amp, there is a washer fluid bottle in there that could have flown around my trunk yesterday and hit something like that module. I don't know how the inertia switch works, but I don't know where to check if it's been activated.

Found the fuel switch, had no idea thats what it was never even seen it before . Car runs, but the it sounds funny and the idle hangs ridiculously long. I switched to the factory tune trying to figure out what was wrong with it, and I took out an IAC copper cap. Is this normal? Does the car have to relearn the idle or something? It's horrible. I can't switch it back yet because there is some 87+93 mix in there from the gas can when I thought it ran out of gas this morning.

I do have one more worry in the back of my head. At my house we have very distinct gas tanks for gas, diesel, and kerosene (red, yellow, and blue). However, because of a possible diesel shortage a while back we filled all the gas cans at one point with diesel.

There was maybe a quarter of a gallon left in the tank and I smelled it quick to make sure it didn't smell like something other than gas, and it looked clear. However, if it WERE in fact diesel, would I know immediately? Is something bad going to happen in the future?