The easiest first: I've known several people who have taken Xanax specifically, as well as others who have taken other benzos. All of that was long term. I've even taken a couple, and none of us have had hallucinations. Should be pretty safe.

Second: sounds like bad anxiety, but you probably have thought that too. Sounds reasonable that the Lexapro is at least temporarily causing it, though we can't be sure. You could ask your doctor.

Celexa made me horribly depressed and anxious and I had a really bad time on it where I refused to go to the doctor for a minor emergency because I didn't think I could emotionally handle it. The switch could be doing it temporarily, or it might be a short term side effect, or Lexapro might not work for you.