I'm sorry to hear that I understand why you would feel disappointed. But as petal said good on you for making the call, because that is a win! and its important that we celebrate the little steps we take.
I'm wondering whether seeing the doctors face may help. I know HotDoc is an app that allows you to book appointments online at a nearby clinic. When you do this you can actually choose the doctor you want an appointment with based on their face and a little description of their likes, interests, background. Maybe seeing their face and reading about them might help in feeling a little more comfortable?
Using this app you can book in a face to face consultation. I know this is a very scary thought but at this stage you are just booking the appointment. Doesn't mean you are definitely going.
Then on the day of the appointment you can just drive to the centre, doesn't mean you have to go in.
And you take it one step at a time like that. You might find that when it comes to going in, you have seen the doctors face, you know a little about them, and it might feel a little less scary.
You always have the option of leaving, you are not trapped there, but if you take it step by step you might find that on your first, second, or third attempt you walk in to see the doctor. And then you've done it!
Its just about taking little steps. Take it slow, and for each step you get closer to seeing the doctor - reward yourself :) and even if you fail and go back a step - reward yourself for trying again.
I had to do this many times with my phobias, just taking small steps until eventually I felt strong enough to do the whole thing.
How does that sound to you?