Interactive process

I asked for reasonable accommodations through a letter to my boss from my doctor. (My disability is not visually seen, I’m HIV+) The next day I was sent a letter requiring me to submit to a fitness of duty test because they were worried for other peoples safety I work with and that I could call the doctors office if I had questions. That was this gist of the letter. I emailed and my boss to ask what the safety issues were, what was the reason for the medical test and to be more part of the interactive process with me. They did not answer any of my questions rather they just kept referring me to the doctor despite my repeated attempts over the next five days. I called the doctors office and ask them if they knew what the tests included and what it was for and they did not. I asked them if I could reschedule the appointment and they told me I could reschedule for the next week. I emailed my boss and told them that I rescheduled the exam for the next week and then they fired me the next day stating I refused to go to the medical exam.

My Questions:
The interactive process I though had to included dialogue between me and my employer?

Does referring me to the doctor to answer my questions count as them acting in good faith and constitutes dialogue during the interactive process?

By me rescheduling the exam should that be interpreted as me refusing to go?