1998 Nissan Maxima All kinds of problems!

Shakes or Wobbles problem
1998 Nissan Maxima 6 cyl Automatic 189000 miles

I was walking back to my car, my hubby and kids were waiting inside with the a/c on at that time I noticed a little bit of dark smoke coming from rear of car. I get in put car into gear and it starts to shake and wobble some at this point the smoking and smell of gas has goptten really bad. The car acts as if it doesnt want to accelerate I got it to about 20 or 25 and thats as high as it would go without vibrating the whole family out of the car. I managed to drive it home we werent too far away. Car cut off once in transit when I came to a stop. Once home it would crank up with a couple tries but when I put it in gear(reverse included the whole car would SHAKE! I got out looked underneath and saw fluid dripping from under the car (to the rear of the vehicle) it smelled just like gas so Im inclined to believe it is! Any ideas on the problem or problems? THANKS :)