Rebound anxiety once the alcohol leaves your system isn't unusual.
( Why Alcohol Causes Anxiety | Anxiety Guru | Hope and Healing )

I have never had an anxiety attack triggered after a night of drinking but I am usually restless the next day. When ever alcohol is involved in a panic attack with me, it's when I'm too drunk. I believe the heavy breathing/smothering feeling plays a role in this as well as alcohol just messing with my emotions. In this case, they are one of the worst panic attacks that I can have because I don't have my rationality intact and have just about no behavior control.

I find that in the morning after I drank that I can get bothered by the strong heart palpitations caused from the dehydration. I also always feel a sort of strange, dissociated buzz. These feelings don't cause me to have an attack, however, but I can see how they could for others.

How much did you drink last night? Were you still drunk when you began panicking or was it during the hangover stage? Are you also taking any other meds?