Hi Xenofayt, I have been through something that bears some resemblance to your story, although my experience was probably a bit milder than yours. However, I think it will calm you a bit down. Long story made short: I ingested a herb called Mucuna Pruriens which contains L-dopa, which is often used for Parkinson's disease. After I had tried it (mainly because it is known to give one a lot of energy and I have been struggling with tiredness for a long time) I started to develop some symptoms and after googling a bit I found out that several studies had found L-dopa to be toxic for neurons in nigrostriatal pathway (which, ironically, is the pathway affected by Parkinson's disease). I got really anxious and started developing symptoms consistent with Parkinson's - I got tremors, involuntary, abnormal movements etc. Also, my cognitive abilities greatly diminished, including working memory and also declarative, episodic memory for events before the incident. It turned out that anxiety was the reason behind it all. Anxiety can among other things cause tremors, tingling, numbness, abnormal involuntary movements, reduced cognitive function. It also makes you biased towards all information that confirms your beliefs, especially information that is threatening to you (threat-oriented bias).

I function just fine now, but it took some time. Based on your story and dosage, I seriously doubt that it will have permanent effects on your brain and cognition. Even though it has had some effect, it might be completely reversible. If you have developed some anxiety (which I would understand completely!) it might make everything seem worse than it is. Also, even though it is only anxiety causing your problems, it will take some time before you function normally again. My advice to you is to worry less and to accept that it is okay to be worried after an episode like that. Try spend your time doing some stuff that you like and try to not keep monitoring (like I did) your cognitive abilities - it might actually just make your recovery slower. So, based on my own experience, I would recommend you to go and do something enjoyable even though everything might seem really "dark" right now. I wish you all the best!