I can't speak to whether it's specifically autistic burnout, but I do want to reassure you that it's real. Stress and chronic shut downs can cause sometimes extreme and idiopathic things to happen with the body. Also, remember that there are multiple stages of burnout even within the allistic community, so the "not enough symptoms" thing makes me side eye and think *they* might just be going along with it, but that doesn't mean you're wrong. Be gentle with yourself. I don't have a lot of advice for this because I've been trying to get myself out of burnout for about two years now because of how bad mine got, but you're not alone, and as scary as it is, the best thing I've found to do is to try to examine your emotions and their sources. Trauma therapy, specifically, has helped me a bit. Dealing with the mind-body connection has made me at least understand where the weird neurological symptoms were coming from, even if I can't really fix them. Good luck, and feel free to dm me if you wanna chat.