How can I increase my chances of getting an appointment? And maybe my assumptions are valid?

Hello, I am a 21 year old woman. Two years ago, I was evaluated in psychiatry for an anxiety problem and I came out with a diagnosis of ADD. After a few months, my doctor and I realized that the diagnosis was wrong. A year ago in February, my family doctor gave me a request for a psychiatric re-evaluation. I called the clinic and sent them the request. After several months of not hearing from them, in October, I decided to call the clinic again. I was told that they had never received the request. I sent them the request for a second time and the receptionist scheduled an appointment for January. This week, one week before the appointment, I receive a call telling me that my appointment was going to be cancelled due to a lack of necessary documents. I call and try to understand the situation, then they explain to me that they did not receive the request and that I had to start the process of requesting the doctor again. I explain that I have sent the request twice. The receptionist tells me that there is nothing she can do and that I will have to start the process over. I tell her that my family doctor retired last November and that I don't have a family doctor right now. She told me that I would not be able to get my appointment because I did not have a family doctor. I then called 811 since I am affiliated with a doctor's bath. A nurse explained to me that another nurse would be calling me later in the week to see if I was eligible for a walk-in appointment with a neuropsychologist. It should be noted that I am studying in the intervention field and I have some ideas of what my diagnosis could be. My symptoms are quite intrusive at times but I am afraid that she does not see the need even though I have been waiting for a year to get this appointment. I would like to share my hypotheses with the nurse without sounding like a hypochondriac.