I'd go through the steering components pretty carefully, starting with the inexpensive steering damper. Doesn't sound like the culprit, but since it's well under a hundred bucks, it's a good place to start. Tie rod ends, etc. Sounds like something is seriously amiss.
Two sets of engine mounts? Why? There is a way of measuring the clearance, and worn mounts are pretty easy to diagnose. Sounds like you might have a "parts tosser" working on your car. You'll need proper diangnostic work, ASAP.
1998 C230 "Black Betty"