My car jerks very badly, thrusts, and makes very loud "pop" like sounds.

I have a Manual 97 Mustang V6 (165k miles).. Last week the car was running fine and always has since I've bought it drove strong.. Drove for a bit, went home, parked in my driveway car still running, flipped it into neutral.. 5 mins later the shift knob started shaking severely, so did the car.. caused by the engine.. it started very fast and weak... Got slower and stronger causing the car to shake, as if it was going to stall.. which it did. died out and gave off a weird smell.. tried to start it up again, it started but seconds later same thing, just died out. The battery is fine, have a half tank of "Unleaded Premium". My mechanic ran a Check Engine Light test, he towed it and had it in his garage for a few days, said I had two bad o2 sensors. he replaced them with new ones. Now the car starts, but it runs HORRIBLE, when I drive it doesnt sound right, it jerks and thrusts very bad, and gives off a, or a few "pop"! like sounds.almost like a firework. It accelerates very slow and unsteady while jerking badly, its horrible.. If I stop maybe 1 out of like every 5 times, the car would shake and stall. I have no idea what it could be.. The night before all this had happened, I was driving in a very bad Tstorm.. I hit a few huge puddles maybe a foot and a half or higher, nothing went wrong then.. Maybe water couldve got into the gas? Cylinders? Plugs? If anyone knows what is causing this, Anything helps.. Thanks in advance!