Dear Welcome to HCM We understand your concerns I went through your details. Please understand that, when you get up suddenly from a kneeling position, it is natural to have a dizziness sensation and you will feel blood draining out of your head. That is quite natural and such a sensation could last for about 5 to 10 seconds. You are already anxious, having anxiety disorder. Anxiety disorder could produce all sort of weird symptoms in the body without medical back up and the patients start obsessing with those. This is what happened to you. You should learn to manage your anxiety. My advise would be to consult a psychologist for anxiety management techniques such as psychotherapy and meditation. If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute details possible. Hope this answers your query. Available for further clarifications. Good luck.