Filled tank with gas and now my van wont run well or even start sometimes

How do you know it is not full? It sure sounds like it might be.

It could be a vapor lock but not likely. Since the introduction of fuel injection vapor lock has been eliminated.
You need to figure out if you are loosing fuel pressure or spark when it will not start back up. Could be a fuel pump relay or ignition module among other things. Even a problem with the vent for the gas tank.

To review - - the fuel pump in the tank pumps fuel to the injectors.
There is a fuel shut-off which works in a wreck to prevent a fire.
If the plunger is down, the switch is on. Normal.

It is possible the fuel lines are full of air which would take a long time to purge by cranking the engine. Sometimes you have to use starting fluid or other means to "run" the engine long enough to get gas back into the injectors.
As long as the engine cranks, the battery is fine.
It is also possible the pump was damaged when the tank was run empty. The pump uses liquid fuel to cool and lubricate the electric pump. It can overheat when running the tank below 1/4 full.
It is also possible the fuel filter was clogged with junk from the bottom of the tank.
I would get someone to check for fuel pressure at the injectors and try some carb cleaner or starting fluid in the intake hose next.

This is your security system. Your van thought it was being stolen. Next time do not leave your keys in the van and lock the doors.

Sounds like you got a tank of bad gas. That would easily cause your issues. Start by draining as much as you can, put a can of Seafoam in there, add a few gallons of fresh gas, drive to the gas station and tank up, and run that tank down until your gas light comes on before adding more. You may end up needing a fuel filter or plugs again, but with minimal run time on the bad gas, you'll probably be fine.

Sometimes you will have to put fuel into the intake to start the motor, then once started the motor will **** the fuel through the lines

undo fuel pipe where it exits the fuel pressure regulater and turn engine over , use bucket and rag to catch pumped fuel , do this for half gallon and reconnect ,, then take spark plugs out and clean with easy start (eather) and replace , should start fine now ,

your fuel pump has died on you

Sediment from the bottom of the tank could be blocking your fuel filter. Replace your fuel filter.

How long did you try for? You might just need to keep trying, the lines were empty from when you ran out and it'll take some time for them to fill with gas. Had the same problem with my parents van.