Stalls on the Highway

Hi,

I drive a 1998 Honda Accord V6 with 117k miles. My check engine light came and I took it to Advance Auto Parts to get a free diagnostic test and they told me I had to bring it into the dealership. So I waited awhile since the car was driving fine and then it stalled on me on the way to work but started back up about 10 minutes later. I took it to the dealership and had Honda take a look at it. They ended up replacing my bypass valves and a bunch of other valves for $502. They even checked my VIN number to see if my electric ignition switch has been replaced yet and it has been since it was a recall. A week after I had it out of the dealership, my car dies in the middle of the highway again. It felt as if I was running out of gas but I still had half a tank left. I had just driven 35 miles after pumping half tank. Usually I can almost tell when it's about to stall because the car feels like it's jerking back while I'm accelerating. When I try to start it the first couple of times after it stalled on me, it would not turn over but it will act as if it's trying to start. Then I waited fifteen minutes and it started back up and would drive like normal except it'd have a couple jerks or pull backs while driving. It used to have a buzzing noise in the back of the car but after getting the valves fixed, I don't think thats a problem anymore.

I'm a 22 year old female college student that has no knowledge about cars untill now, I'm starting to learn quite a bit and I really need help. I took it back to the dealership and they even told me they can't help because it's not acting up. Yet. So could it be my fuel pump? Please help me!