Well, the good news is that you figured out what is wrong. You still may be okay, not all is lost yet.
Years ago I helped an owner of a reputable repair shop with a customer who had filled his Dodge VP44 truck with gasoline (about the same amount as yours) and drove it until it died, which was not very far.
I drained the fuel tank using the shop's transfer pump. I dropped the pump's inlet hose into the filler neck and pumped out as much fuel as possible. I then used the truck's lift pump to remove the remaining fuel in the tank by disconnecting the fuel supply right at the inlet of the VP44 and extending the fuel line into a fuel container. I ran the pump in cycles until just mostly air was being pumped.
I poured five gallons of fresh diesel fuel into the tank and used the truck's lift pump again to remove any remaining mixed diesel / gasoline solution from the fuel tank. Then I filled the tank completely full of fresh diesel fuel. I changed the fuel filter. I used the lift pump to prime the filter housing while continuing to return the fuel into the fuel container.
I reconnected the fuel line to the VP44 and cracked a couple of injector lines and fired up the engine. Engine ran smoothly and as far as how long the VP44 injection pump lasted is unknown, but the truck was still running fine six months later.
You should be able to use the contaminated fuel for off-road gasoline powered equipment, such as mowers, gasoline powered tractors, ATV's, etc. - anything that isn't modern enough to use oxygen sensors. Just use small dosages each time you refuel. Also, the contaminated fuel will be great for starting burn piles. I am sure that you have friends that will be glad to take the fuel off your hands.
- John