Im really sorry that sounds so hard! I have to say if I was in need of therapy and my therapist left for a long period of time, id expect him to find me a replacement. Did she offer this? At least while your t is gone you would be developing a relationship with someone else so that in worst case you have someone if your t doesn't come back. This would really bother me. I read it like this could go on indefinitely, if she hasn't given you a name of someone I would ask for someone until she returns.