Hello, on Sunday I was expierencimg some rather powerful pain in my right arm, since then, it went away but then my arms and legs have been weak... I can loft, write, type and everything but over the week I have had very tired limbs, to the point to where walking up stairs is feeling like a work out. This has all happened over the course of a week. It seems to be getting worse. My torso twitches quite a bit but I'm thinking it may be from my 100mg of Zoloft. I'm getting scared... very scared. I am 17, not very active and has Generalized Anxiety disorder. I'm also having difficulty with balance but have perfect coordination and reflexes. What could this be?