I was driving and when approaching the red light,I was slowing down and suddenly

What is your question?

I was driving and when approaching the red light,I was slowing down and suddenly I heard a loud noise from my car sound like something just broke or snapped,and right after that it picked up was very weak and the speed was reduced to half compare with some other times before this happened. My question is what was happened and is it easy to fix? Thank you

What makes this problem better or worse?

the car is dirven at a limit speed even I step hard on the gas pedal