Truck won't start.

[Big_Mike04]

I have my 04 F-250 6.0 and it cranks but won't fire.
Back story.
Friday i got up for work and went out to warm the truck up. I noticed it cranked a couple of seconds longer than normal. When it does this i dump a can of sea foam and it clears it up. So after work i grabbed a can and dumped it in.
Saturday no problems.
Sunday my wife takes it to town shopping and has no problems.
About 4:00pm i plug it in for the next day work. At 5:00 my wife says she wants to take my son to youth group. So i get in to move it up to the house. It starts just fine, but as i back it up it i push on the accelerator and it goes to the floor and does nothing. I put it in park and try to rev it up and the rpms just climb very slowly.
So i leave it sit there for a couple of minutes and it starts to run really rougb and bog down. The truck starts to shudder and dies. It won't restart.
i call my cousin who knows a little bit more than me amd he suggests that it might had gelled up. So i got a bottle of 911 and dump it in the tank and poured some in the fuel filter on top of the motor.
I let it sit for a few minutes and try to start it. It cranked for a bit but then fired up. It ran fine for about three minutes, but then started to shudder again then it died.
Has not started again.
i have put heat under it. The fuel filter on top has fuel in it. Not sure what it can be.
take any advice i can get, before i take it somewhere and let someone else mess with it.
Thanks
Mike