When I adopted my first GSD she was 6 months and would do the same thing. Destroy anything she could get her teeth on etc... we knew we eventually wanted another dog and when we adopted our 2nd GSD she no longer freaked out. She just needed a Friend! I know that's not possible for everyone, but that is what worked for Sierra.

There are plenty of holistic things you can use in the place of drugs;
Rescue Remedy
http://www.doggiesparadise.com/rescue-remedy.shtml

DAP Comfort Zone plug in
http://www.allivet.com/Comfort-Zone-...ne-p/15112.htm

just google: holistic stress relief in pets, it gives you tons of websites.
Good Luck!
Do you have any pictures of her? What color is she?