Talk to Cardiologist on Pain In Left Arm And Chest

I have pain in my left arm and chest. It started in October. I was eating and suddenly my heart was so strong and fast that I thought it will stop. The same happened with me in November. Pressure on the chest, through the ears, very fast heart beat. I went to a cardiologist. My ECG, Echo and treadmill stress test are all clear. Now the pain my chest is there. It's spreads to my left arm, neck and back. Doctors say that I have anxiety. But my pains are real. Like I knew that my chest hurts. The left side of my back also hurts. It feels like a pulled muscles. Should I be worried?