Anxiety is very common in withdrawal - I also think it's pretty normal to feel anxious if you went to the hospital a few days ago and they told you could have died.
How long it might last depends on a lot of factors - like if you were anxious in the years before you started drinking, or whether this is a new thing that's happened recently.
If you're finding it debilitating I really recommend you see your own Dr. - they may be able to help at put you at ease
D