Diagnosis experiences

Hi, I'm relatively new here. I have suspected that I might have ASD for several years and am looking to get an assessment to make sure. I think the symptoms describe me very well, and I would like to know the answer. However, on the majority of NHS and private clinics websites, they would like you to bring a family member for the assessment. And I feel the request to bring a family member is a major barrier. One reason is that there is so much stigma associated with ASD, I am quite sure my parents would not want me to get a diagnosis. Some clinics do offer assessments without relatives' involvement, but add that it sometimes may not be possible to reach a conclusion without enough information. I don't have any close friends I can take with me to the assessment either. I was wondering if anyone has ever been through a diagnosis assessment alone and can share their experiences. This would be very helpful!