need help

I have had fibromyalgia for many years but recently have developed a new symtom.  My body starts shaking kinda like tremboling.  I feel it in the center of my body through my arms and legs.  I have had the muscle twitching and spasms, but never anything like this.  If you have had this happen I would appreciate if you could tell me what you did that helped with this I would really appreciate it.