Recently went out of town in my 97 Windstar and ran out of gas, but the gauge read half tank i thought it was broken , so walked to the nearest gas station and put 2 gallons of gas and it started, went to fill up again and filled up with 18 dollars when it usually fills with 33 or so so i know it still has half a tank and is not the gaage cause wheb I filled it up again the gauge went to full, now i dont know what the problem could be any help would be appreciated.

I guess the first thing I'd do is replace the fuel filter if you haven't lately. Then wait and see.

Hope it can be a simple fix. But.......

Had a friend with a GM vehicle with similar problem. Turned out that the fuel line in the tank that provided input to the pump developed a small crack. When the tank fell below appx 1/2 the line could suck air and the engine would quit. Hope you can come up with an easier fix.
Good luck