I also had a very similar thing happen on Lexapro. It was almost painful to sit still and I was very agitated. At first I thought it was akathisia, but it was a mixed episode according to my doctor. Whichever it was, definitely was caused by the Lexapro and got worse with an increased dose. It stopped after I tapered off of it. Also, I had a much milder version of it happen on Adderall awhile back.