What Causes Palpitations Along With Weakness, Dizziness And Chest Pain?

palpitations problem almost everyday: and when it occur i feel like weak,tired, sleepy after, lightheaded, left chest pain- left back pain, urge to go to bathroom, sometimes nails got bluish.. but i ve done a lot of ECG the previous yrs and also last yr., and the result were normal.. but one of the doctor find me that i have an acid reflux,. so i am confused of what really is the main problem of why i am having this palpitation and aching on left chest,,,.. can you answer my problem?? thank you a lot.. hoping for feedback. by the way i am 24 yrs of age and a female..