I recommend you contact a dealer and order a new ignition lock cylinder at your earliest opportunity. The dealer will get the correct cylinder based on your vin. In the interim, you will have to wiggle the key as best you can and try to get the lock to turn. If you can't get the lock to position 2, you are in a world of hurt. The cylinder comes out fairly easily when the switch is in position 2, otherwise, you may have to drill the lock out. I would personally leave the car parked if you can't get the key to turn except with much "finesse-ing" of the key. Try holding the key up towards the top of the cylider, that works for my aging 1980 300D usually.
A chassis manual will detail how to get the cylinder out. You can fabricate your own tool for the job as described in the manual, just make sure you use the strongest wire you can find. I used a heavy duty paper clip but a dealer friend showed me the real tool and it's very stout wire.