I also deal with a lot of anxiety, The good news is that it means your brain is telling itself that it needs to start producing the right chemicals for your brain to work right.
It is a natural course of things to happen as our bodies slowly adjust to no longer being bombarded by alcohol.
You will get through it, we all do. If you can keep yourself busy, go for a walk, get outside, go to a meeting, you will probably be able to divert your anxiety a little.
You should defiantly read up on PAWS. there is some great info here and on other sights on the internet.
the anxiety will last as long as it needs to, unfortunately, it is just the body adjusting. But the advice above is right on, breathe deep, relax and do not give in to temptations, as that will only make it worse in the long riun.