I have stolen off of people before when i was younger. I believe that for your own sake that you should be completely honest with the girl and tell her about what is going on with you. Tell her that you apologize and this will consist of an early ammends for you. From what you have posted im sure they know. But something important that you realize is that it was not you who did this but your disease. Honesty is the best medicine and even though you have lost her trust and it may take a long time to regain if ever. It can be done, but acting as though you never stole it you are lying to her again and yourself. Sorry if im sounding blunt, thats not my intention. I was just expressing my sentiments and i hope that i was of some help for you. Good Luck