Why cant I pump gas?

[brown78]

Alright, I'm feeling quite stupid at this point, I need help pumping gas into my truck. Seriously, not a joke. Every time I pump gas it will overflow out the filler. I took the filler tubes apart, no obstructions in the line, blew compressed air through the filler and vent tube, seems fine. If I barely put the nossel into the filler and pump slow i get gas into it, still makes a mess. Any have any suggestions as to why it wont take gas? also the pump don't shut off like it should when the tank is full, just throws up gas all over the side of my truck What am i missing here?