I'm not sure I understand all that you wrote, but this sentence about your fear made me think that this could be something you work on in therapy with your current trusted therapist. You have a year before you will be moving, so could this concern go to the top of your list in therapy? You could create an exposure hierarchy about IOP and work your way up. Perhaps the culmination could be a "field trip" to an IOP and spending the day there as a guest so you can see firsthand what an IOP program is like. Before that, you could do other steps on the hierarchy, like thinking about or visualizing the IOP while present with your T, so she can help with anxiety symptoms and you can practice your coping skills, etc. If she doesn't do exposure hierarchies, she probably has some other method she uses to work with patients with phobias. Good luck.