If you have thick milky crud in the input side of the filter, you have a lovely combination of water and dead gas (the detergents don't evaporate and emulsify the water) in the bottom of the tank.

Siphon out what gas you can and pull the strainer, you won't get very far until you get the tank clean. That slop WON'T go through the filter, and you DON'T want it to -- new fuel system parts when it get them clogged up to!

Peter