Imposter Syndrome

Hello, I am about to start the assessment process and am excited to get some answers but also petrified that they’ll say I’m not autistic. Does anyone have any advice for this? I’m pretty sure I am autistic and so is everyone who I’ve told but for some reason I still feel like I’ll not get the diagnosis. My head is a mess at the moment, I’m trying to think positively and that it’s most likely I will get the diagnosis but then the imposter syndrome just chips in and says ‘but what if you don’t?!’ Ugh it’s so frustrating. I think also because I’m AFAB I’m worried my assessor won’t understand masking and just rule me out. Any help would be much appreciated :)