Why I'm screwy

My Explorer has been acting up for six weeks now. It's some kind of fuel system problem: If you let the gas get too low, it won't start, altho' it will crank fine. Twice it's stranded me and I've had it towed to the mechanic only to have him tell me that it started right up in his shop. He thinks the fuel pump is going south and freezes up when the gas gets too low, then gets going again after getting sloshed around on the wrecker. But he isn't sure and an in-tank pump costs $500 to replace, so we figured we'd just wait until the silly thing breaks down conclusively.
Well, this morning it wouldn't start. Again. Of course, Nicholas and I were running late for school. So I gave it some gas and tried again and viola! it started right up. But the minute I took my foot off the gas, it died again. After decades of riding in and driving unreliable cars, I made do. (Aside: I remember taking a rich girl on a date in the family station wagon, a car with a leaky radiator that you had to top off every time you got into it or risk overheating the engine. There wasn't a second date.)
I pulled the Explorer out onto the street, driving with two feet. One was on the gas, keeping the idle near 1,000 rpm, and the other was for braking. I always hated having unreliable cars, so I've been pretty good about buying good vehicles, maintaining them well and promptly repairing problems. But not this time.
I never called my mechanic today. I wonder if it will break down on me tomorrow...