Hi everyone. I am having some terrible sensations from my heart. Its not like when we do excersice or have a fright and the heart races it feels like my heart is filling up with blood and is going to stop. This happens one after the other, I am ok when I am walking or excercising but I am noticing its when I am not doing anything. I feel my whole body is so tense to the point of being stiff. Just wonderded how people describe thier symptoms. Have justed weaned off sertraline as GP said it may be side affect. Getting really worried which I know does not help.