I Was Prescribed Propranalol Over Four Years Ago To Use

I was prescribed propranalol over four years ago to use as needed but totally stopped over a year ago. I've been taking it off and on since sept and working out and working with elementary kids in PE. Lately I've been having symptoms of low blood sugar, can 10mg propranalol be the problem. Planning to stop using it. I stopped before and never experienced any serious issues until I started taking one a day when I went to work