Unfortunately you will have to find a mechanic who knows something about vehicles...Too bad that factory trained technician isnt any help!
You said it started once when you put your foot to the floor?
On ANY fuel injected vehicle when you crank the vehicle over you are giving it fuel. The longer you crank it the more fuel you are giving it. That's if the fuel pump is working fine.
By stepping on the gas pedal you arent giving it any more fuel (myth) You are actually giving it more AIR! And as vehicles get older sometimes they need more air. I could go more into it as to how the computer is supposed to compensate for that...but that is another story lol
If you have any one in your family who is mechanically inclined get them to do a tune up! This would correspond with the needing more air and the vehicle getting older.
You always should start with the basics and go from there! And unffortunately the basics would be a tune up. I know you say you are a poor single mom. Start with some spark plugs and an air filter if cost is a problem.
Pull the dipstick out and see if the oil smells like gasoline. If it does....Do an oil change before you do anything else!
If it is flooded (too much fuel) then it wont start either. and this goes back to the AIR thing....
If you ever suspect your vehicle is flooded. Hold the gas pedal to the floor and it shuts off the injectors and is called a clear flood!
This might sound like a lot and I apologize. lol
So start with the basics...Oil change and spark plugs and air filter. Even if it doesnt fix the problem...you always need those and save you money in the long run!
Hope I was some help and good luck!