As upsetting as it may be, at least you now have some clarity about the situation. Please keep working on taking good care of yourself. None of what she is doing is any reflection on you, however it might feel right now. Rehab relationships rarely end well, for either person. But she had made her decision, and YOU have a wonderful life to look forward to. Allow yourself time to grieve and to process and to heal, and things will start to look better.