Well, I don't think you messed up, you just got a little too anxious. After pitching your yeast it may take a day or two to see fermentation results, especially if pitching at colder temps into a lager. The yeast are active, just not enough activity to see.
Since your airlock is still bubbling your fermentation is still active. Primary fermentation on a lager can take 2 weeks, and sometimes longer depending on primary temperature. Don't transfer to your secondary until your primary fermentation is complete. Check you gravity to be sure.
As for overpitching, not possible with 2 smack packs. If you would have taken 1 smack pack and make a starter you would have pitched much more yeast than is contained in 2 smackpacks. This is something you should try for your next lager. Fermentation should then start within 12 hours vs. 3 days.