When I first started looking for good T's I could only find one good one near the places where I live (I live with my parents if i need to, but I go to uni in a different city so I travel a lot between the two places), and there were only two good places i could find, but they either had a waiting list that was completely full or took over a year of waiting. I don't know if this is an option for you, but for me my current T helped a lot in finding more places I could go to. when I would sign up by myself I almost never got a response or I had people tell me they didn't really know anything over the phone. but when he signed me up as a patient of his that was looking for better help, I got responses immediately and I got over the phone intakes to see if they would really be able to help me once I get through the one year waiting list. I know your situation is a lot different than mine since I live in/next to two of the main cities in my country (I live in a small country so don't be too impressed by the word city), and your T situation is very different, but maybe if your T says that she doesn't believe in DID you can ask if she'd be willing to help you find someone who does believe in it? I don't know if this is possible in your situation, but if it is, maybe it can help a bit. or maybe you can see if you can find someone in the same organisation who is more open to the idea of DID and is willing to learn more about it. also for this i don't know if this would be possible for you, but maybe seeing someone who is open for it is more beneficial than seeing someone who doesn't believe in it at all.
And about the thing with your T, I totally get your situation. I see my T once every 3 weeks and the only thing we've done is trying to get me in touch with my emotions, while i'm trying to make clear to him that i don't have any problems with my emotions and it just looks like that because of all my other issues. The cutting down on appointments, also doesn't sound like the best idea ever, so if you can you should really try to go against her doing that.
But all of this is very easy to say from an outsiders perspective, and when it really comes down to talking to my T about them I'm very chicken and i can't give them any form of criticism, so do with all this what you want. i just hope you can find some good help as soon as possible and have a safe space where all of you feel comfortable enought to talk and make some progress.
Good luck,
Liz&Kat