I've been feeling unwell for the past few days. Feel like my heart is just going to give out on me. I had a 24h ecg almost two weeks ago and dr said all is well, but I still feel like something is wrong. I feel faint, my left side of my neck hurts, feel like I can't take a deep breath, and my left arm goes numb. My bp and heart rate are wishing normal. I really hope it's just anxiety and not something more serious.