I expect that your problem is tires. Either they are out of balance, or there is a serious problem with one, such as a broken belt.
You can check the front end for tightness if you have the proper equipment such as a floorjack and jackstands. If you do have such equipment, raise the car, suspend the front wheels, and shake and pry on everything to see if you can find something loose.
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in