While driving there was a pop noise, smoke was coming from the back of the vehicle and it is leaking fluid?

Yesterday my car was making a grinding noise and slowed down as if the brake was being applied every time I drove. Today I decided to try to drive and when I was driving heard a pop and then noticed smoke in the back of the car. I thought that a tire popped but after looking both tires seemed fine, and I noticed a leak towards the transmission and back wheel axle. I am currently stuck on the side of the highway and need help on understanding on what it is and if I can get it anywhere.