If your wool has shrunk from over agitation or a temperature shock, what you will need is a big bottle of conditioner (get the cheap stuff, you don't need anything fancy). Fill your sink with lukewarm water and add half of the conditioner & your wool. Gently stretch the wool back to the right size/shape. Add more conditioner if needed. Once you are satisfied its back to its normal size, hand-wash the wool with your usual wool wash. You will need to also do an extra rinse using vinegar (about 1 tablespoon) to help remove any remaining conditioner that could interfere with the performance of your wool.