I find it helpful to keep an old mouthpiece in my van so I can buzz as I drive. I also do the pencil in the lips routine. These things don't take the place of practice, but they help build your chops up. Just remember, it's going to take a lot longer than a few weeks to get it all back. I hope to be improving right up to the day I can't lift my horn to my lips any more. And like SFPat said, join a band or church or SOMETHING. It's different somehow if you HAVE to do it.