Lexapro Panic Attack?

Hi guys! I have been on Lexapro for about 7 weeks now, started at 5 mg and went to 10 mg after 3 days. I got prescribed because I started having panic attacks at work and bad driving anxiety to the point that I was kind of paranoid. The first two weeks were a weird adjustment but then the lexapro really started to help me. I felt like I could go to work without worrying about being anxious and I could actually do my job! Total game changer. Well two days ago I had the worst reaction ever while working. Im a bank teller, so I was helping a customer with a transaction and I could feel him staring at me like I was taking a long time to complete the transaction. Then I felt my neck stiffen up, and it felt like I couldn’t even move. My whole neck and shoulder area was completely frozen. I have never had that happen before. I went completely mute for the remainder of the transaction and couldn’t even look the guy in his eyes. I felt totally paralyzed. My hands started shaking and I felt like I was on MDMA. It was really scary. I broke down at work and had to leave early, and honestly I am so embarrassed and anxious to go back to work tomorrow😭 Has anybody had this reaction before?