I'm not sure doing the work yourself is the best idea. Properly stabilizing and jacking a house is not an easy task, but it quite do-able. The problem comes with the stick framed area more than the timber framed section.

Depending on the extent of the damage, you may have to both remove the floor, and expose the sills from outside. Whatever you do, I would recommend borate treatment of any wood that is left as is, as well as any new wood that will be in the damp environment of the crawlspace.

You might want to hire someone to appraise the damage and recommend the required repairs first hand.

Good luck and work safe.