I am very anxious n in stress from some time.from last 6 months suffering from shortness of breath,weakness,left hand trembling n when worried in my left hand,left neck n left chest feel some weakness n shaking nerve(is that palpitation as I don't know) n it suffers me a lot.i consulted physian, neurologist n did my blood test n ecg  last 2 months back n results came normal.doctor told me to not worry all is ok.but still I face left hand n chest nerve trembling kind of thing.for that sake I got tense n my heart beat raises n thought of having heart attack.please help me what I am going through n guide me what should I do.is it anxiety only causing me problem r anything else?