1999 Jeep Cherokee

I have a 99 Jeep Cherokee Loredo with a straight 6 4L engine. I bought about a month ago. This all seemed to start the first time I put fuel in it! I filled the tank and it over flowed from the top of the tank and for some reason became difficult to start takes 2 or 3 times of trying to start before it does. I took it back to the lot the replaced the fuel tank but when I got it back it is still having a hard time starting and is now stalling out on me it mainly seems to happen when I am trying to take off from a light or trying to give more gas to pass a car on the freeway, I loose all steering when it stalls but seem to still have radio ect. I have just been throwing it in neutral and restarting it! I dont know a whole lot about cars but cant afford to take this in to get it fixed so any suggestions would help Thanks