I am not certain, but I don't think that freighters will reliably deliver more fuel than what the station's fuel cells can hold (and from past experience with stations in deep space I wouldn't necessarily count on even that much). If you want permanent forward refueling points, I would strongly advise you to try to find convenient fuel deposits and build gas mining stations (or starbases with gas extractors) on them. Resupply ships also work, and have the advantage that you don't need to find a conveniently-located fuel deposit; you can just deploy the resupply ship at a fuel deposit long enough to fill its holds and then move it to the area you want it and deploy it over any convenient system body (asteroid, gas cloud object, planet, moon, star).
Energy to fuel converters would broaden your options for permanent refueling locations to any convenient stellar entity (gas cloud, star, supernova remnant, black hole), but they're at the top of a branch of the tech tree that I don't prioritize that much.
One last thing you can do, although it might be considered to be a bit of an exploit, is to take one of the state ship designs and add docking bays, cargo bays, and gas extractors to it. Order it to mine from a fuel source to fill up its holds, then order it to wherever you need it and you can order your other ships to refuel at it. Note that it will automatically return to the nearest spaceport to drop off its cargo if you allow it to fill up its cargo holds, that unlike a real resupply ship it will not filter the resources it mines to take only the hydrogen and caslon, and that it will not automatically resume mining operations after automatically dropping off resources or being ordered to do something else. If I recall correctly, it is also unable to refuel itself from its cargo bays, whereas stations and real resupply ships can.