Vitamin B1 anxiety reaction?

I haven’t been diagnosed properly but suspecting mild CFS and/or histamine intolerance. My main problems has been severe brainfog, headaches and brainfatigue for almost 9 years. I get immediately worse after cognitive and physical exertion but don’t really know if it’s PEM in that sense. Have felt a more body fatigue the last year. I also have autism level 1 and ADD/ADHD so there’s a lot going on and could be autism burnout as well. Very sensitive to stimuli of all kinds.

However, I’ve tried a lot during the years and a started taking vitamin B1 yesterday, it’s 100mg Hcl. I got more energy pretty fast in body and brain but felt little overstimulated and even more today with more anxiety and feels like 10 cups of coffe. I took it with some cofactors (electrolyte pulver with potassium, sodium, magnesium..)

Is this a normal reaction in the beginning or does it tells you something else? I’m overall very sensitive to stimulating stuff and has history of c-ptsd.