Dear Welcome to HCM We understand your concerns I went through your description. All addictive substances has a chance to create nervous agitation. Redu bull also false under such category. Addiction always causes nerve irritation, triggering so mny negative hormones inside the body which makes us so weak that we become unresponsive to nature. Anxiety arising out of this situationn is another risk. When we are aftaid of substance abuse and we do it because we can t avoid it, we start fearing there might be something wrong, or something might go wrong. This fear creates anxiety, even through without any knowing perception of comprehension about such thoughts. Such anxiety causes symptoms like plpitations, sweating, numbness, pain around chest, shoulder or neck etc. You are under such anxiety symptoms. Nothing to worry. You already had decided to visit a doctor. Do it, he will give you further advice. Hope this answers your query. If you need assistance of a psychologist for anxiety, feel free to contact me. Good luck.