This is normal, fasting increases catecholamines aka Adrenaline/Noradrenaline(Epinephrine and Norepinephrine respectively) basically putting you in a “fight or flight” mode.
This also heavily contributes to the clarity people experience when fasting. Some people will have a harder time with these increasing than others, best advice is obviously to be in a good state of mind in other areas of life, some people recommend a magnesium supplement.
This happens to me sometimes too. It sucks. Idk, sometimes it helps to go for a walk or play a game on my phone. When I’m able to I remind myself that it’s just how I feel in the moment and it will pass.
I will go out in a limb and say that anxiety is not a normal side effect of fasting? You should have that checked out as a separate issue.
Some people have good results supplementing with micro doses of Amanita Muscaria. Look it up, if it sounds like something you would like to try Pm me and I’ll send you a few links on the subject.