Here is what I found online for the connection between Benadryl and anxiety/panic attacks. First the not so good.
Source(s):
Wiki. Here are some more side effects.
"This leads to profound drowsiness as a very common side-effect, along with the possibilities of motor impairment (ataxia), dry mouth and throat, flushed skin, rapid or irregular heartbeat (tachycardia), blurred vision at nearpoint owing to lack of accommodation (cycloplegia), abnormal sensitivity to bright light (photophobia), pupil dilation (mydriasis), urinary retention (ischuria), constipation, difficulty concentrating, short-term memory loss, visual disturbances, hallucinations, irritability, itchy skin, confusion, erectile dysfunction, and delirium". I don't like the sound of that.
Secondly, that some Doctors use Benadryl to treat anxiety and panic attacks. Interesting to read.