Does it seem like its running rough or does it just shake when you put it in drive? If its running rough I would take it to another mechanic and have them run a diagnostic on it. Sounds either a sensor, or wire was broken during the accident. If it seems like its running fine but just shakes when you put it in drive then it sounds like you broke a main motor mount, transmission mount, or there is a crack in the subframe (unlikely). I hope this helps and you can find your problem.