Weird pressure inside car, occasional loud popping sound. HELP. - 2012 Sentra

Two weeks ago I was driving 25 mph and suddenly there's a sudden pressure change inside of the car. It's like the air got super heavy, as if the car was going through a seismic wave. It left me with this horrible numbing sensation all over my body, it was that bad. Then, I heard a super loud pop coming from the back of my car. It was the loudest sound I've ever heard, and it literally deafened me for about 30 seconds. I seriously thought I was dying. I checked to see if I just drove on anything, and I didn't.
Well, I didn't really do much about my incident except tell my mom, who just laughed. My car seemed to be running fine for a week after that. And then, as I was driving, I felt the heavy pressure again, so I immediately stopped my car. I gave it a little break, and then when I started driving again, it came back.
Then, after a few days, I was turning at a stoplight and the pressure came back, and there was a pop that came from the front of the car, not as loud though.
I pulled into a parking lot, and saw a large plastic piece from the bottom of my car that was clearly out of place. There was a little bit of dripping from under the front of the car, but it stopped after while. The car drove fine after every incident though.
My car is a 2012 Nissan Sentra. I bought it at an auction place for about $9,000. It was in an accident before, but we just had to replace the right side doors. All of the break fluids and windshield wiper liquid is perfect. The car has had regular oil replacements. I just had the oil replaced yesterday, and they checked everything in the car except for the exhaust system and some kind of pipes. Everything was satisfactory.
I need help asap. My parents think I'm delusional because everytime they drive the car, nothing happens. It just happens at random times. I feel like I'm in a dangerous situation and I don't even want to drive that thing anymore.
Somebody pleeeease help me solve my car mystery. Like, I don't even know what to do anymore.