Thank you for your query. Your symptoms point to an acute strain on the heart. Please refrain from any strenuous activity including masturbation and sexual intercourse until you get examined by your physician. Masturbation involves a lot of muscle stain and hormonal effects on the body. It is normal to have a fast heart rate and milder versione of your symptoms during and after masturbation, for a couple of minutes. However, your symptoms seem severe. If you are overweight, diabetic, hypertensive, dyslipidemic, a smoker or other substance user and if you have a family history of heart disease, your risk for cardiac pathology increases significantly . I recommend you see your physician to rule out cardiac pathology. what alerts me to suspect problems is that you felt it was bad enough to seek medical advice. Trust your instincts, take it easy and tell your doctor exactly what you felt. Take any relevant information or medical reports, if available. hope this helps. wish you good health