How to wash a wool coat properly? -_-

Hi!
I'm looking for a bit of help; I just bought a second hand coat made of wool. As I always do I machine washed it and came out totally shrunk...
It never happened to me yet, I'm so angy at myself! I used the fragile programm with 30° water and low spin-drying.
I'd like to know if there is something I can do to give it back is original size...
Thanks a lot for your help :)