While commonly called anti-sway bars, these are correctly know as anti-roll bars. This aside, someone here may be able to diagnose your problem from your post, but if you do not have any ability to get the car off the ground and after yanking on the suspension memebrs, verify the cause, I suggest taking it to a compentent shop. Do a search for recommended shops in your area. However, if you are determined to tackle this yourself, for whatever reason, you've come to the right place; mercedesshop members are the best!
regards,
Mark