Dizziness, Nausea, Palpitation, Muscle Weakness, Breathlessness. Normal Tests. Suggestions?

Dear Doctor I have been having disiness since September occassioally followed by nusea once a week until 22 Nov I was so dzzy whole day, then 01 Dec nuseaua all day until 12 December when I got, dizzeneas, heart palpilation, diahrea, muscle weekness, extreme fatigue , shortness in breath. I have doen bunch of blood, stool.Urine tests as well as chest xray and brain CT scan and all normal. I still have above symptoms rotating in different days, Is there any suggestion ? I have started gluten free diet since last weeks to see whether that helps. thanks very much for advise.