Hello, My Right Upper Thigh Began Twitching Three Weeks Ago.

Hello, my right upper thigh began twitching three weeks ago. (No change in daily routine, sleeping well, minimal caffeine consumption etc) the twitching stayedin the same location for three days. I then started, and continue to have, body wide twitching. Majority of the twitches are still in my right thigh/leg but I now I have twitches pop up all over. I suffer from pretty severe medical anxiety. Needless to say I began researching "muscle twitches". I am terrified this is something sinister (ALS). ( I began taking magnesium two weeks ago with no change in syptoms. I also have been prescribed Klonopin for three years (1mg daily). I began a very slow taper in June. I am down to about .125 MG daily. Could this be the cause? Why is it primarily in one leg? Should I be considered about a neurological disease ALS or MS)