You've taken the right steps, changing fuel filter. It is most likely the fuel pump. Not too tough to drop the tank and replace it. Just be sure you inspect the inside of the fuel tank with a flashlight to verify there isn't corrosion forming in the tank lining or the replacement fuel pump won't last long.
You should be able to leave the driver's door open and hear the fuel pump come on when you turn the ignition on. If you are still trying to drive it, you might be able to listen if the fuel pump is on at the times it doesn't start.
Matter of time before the fuel pump quits altogether.
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