Oh this is really stressing, I’m sorry ;-;
It wasn’t hard for me, I got tested as a kid, I didn’t get my diagnostic back there but when I got tested again it was with the same person, so this really make a diference.
Also almost everyone around me (family, teachers and other doctors) told me that I was autistic, so for me it was easy.
I don’t know what to say, perhaps you should look for someone who is specialized in autism, I’m not sure how this works on your country but here at Brazil the person who tests autism algo work with other things, so finding someone who works ONLY with this might make it easier.
Hope this help, good luck !