I wanted to add, I have just found out that wheat has been connected with anxiety, anxiety attecks & panic. Apparently, since the 60's, wheat has been GM (genetically modified). As difficult as it might be, I'd advise anyone with high anxiety, to cut out wheat from diet. At least, try it for about 1-2 weeks (usually 2 weeks gives visible results).
Bach flower remedies Aspen (unknown fears), Mimilus (known fears) , Cherry Plum (fear of loss of control), Red Chestnut (fear for loved ones) & Rock Rose (terror, extreme fear, although Bailey Essence Cyprus Rose is deeper acting) are for different fears. Although they say its better to take flower essences which are made closer to your own living area, so for those in USA, I'd take the FES range.
Of course, caffeine is a big culprit also. I noticed this 20 years ago, since then have cut out caffeine (ESPECIALLY ☕ COFFEE) & it's much better. Even decaf can & does exasperated it, but for some reason, turkish coffee (made the traditional way) does not give me anxiety. I believe it's the acid in the coffee.
Breathing exercises are a great help too but it's difficult to even breathe when one has anxiety, but a very important note here, don't force breathing, breathe from the belly (like babies!), as breathing from the upper diaphragm exasperates anxiety.