2000 S-10 problems

Hi! Im Jeramy an insurance salesman in okc although I work with cars everyday im not to familiar with weird complications. I keep up with the basic maintenance up on the car as in it has 94k mile. My car has been acting up and I cant figure out what is wrong with it. The problem is whenever I am driving after about 15-20 minutes of driving my car will start to act like it has trouble going and make a popping sound from(not a grinding sound but more like a backfire but way softer and from the front) what I think might be the left side of the engine. The popping sound could come from somewhere else because I am only hearing it through my window. Also I will push on the gas and the engine will not go and it feels like its reving slightly not loud tho. But will idle just fine this problem occurs after driving on the highway and then finally coming to the first stop. There is no check engine light so I havent been able to get a scan on it. But I know there is a problem but I dont wanna take it somewhere and have it not fixed again. Because I have already spent 300$ and nothing has fixed the problem. My thinking is the fuel pump or transmission. But I dont know for sure or even if that is the problem. Please help me im begging I dont have a lot of money to throw around and I came across this website. Made the donation and I will consider a more generous offer in the future if you are helpful and will consider using this website as a future reference.