One suggestion is to get her in for treatment if you can, and if not, then try talking to her about it, try leting her Draw out her emotions. She needs some sort of realize and that's why she is hitting herself on the head. (at least that's one opion)

As for you, you really need to set the example and not cut. Or she will learn it from you.... Becareful. i know it's tough, and I haven't been through a divorce or house foreclosure. But Grief and the holidays, I've gone thorugh. and after some time you find a way. With the Holidays fast approching. use the new year for a new you. Keep going with NOT cutting. and make it a year with out cutting. Focus on keeping yourself well, and helping your daughter to deal with it. But do know that You and Her still have the memories of both Grandparents. Remember the good times, and dont' be afraid to talk about it. Keep going. you can get through this!!