the first question that pops into my mind is why is she your fiance? it sounds more like you would be better off as friends. you could still support her and her son in that role but you would not have to live with the negativity that encapsulates her life. if you truly want the relationship, making the best of all these counselors is the way to go. one thing i discovered, having ptsd myself, is that you really need a counselor that specializes in trauma to treat it. i spent three years in therapy not getting anywhere with a therapist that i felt was good, but he wasnt effectively addressing the ptsd. my anxiety has been greatly reduced now that i am seeing someone that specializes in trauma. and then regular visits to the couple counselor to be able to communicate your feelings would help improve the relationship.