Sorry to hear about your extremely difficult and upsetting situation . No family should have to experience this but especially given your wife's young age. I don't think for one second that your wife would feel that you haven't protected her, you are on here expressing your feelings of helplessness, you clearly care for her very much and I'm sure she knows that. 
Although I cannot change your situation , I would like you know that this forum is always here as an outlet of support. We have all needed that support from time to time so there are so many people here who will support you,

best wishes