I've got a question, I'm 25 and during sex I finish really quick. I mean within 15 - 30 seconds. Do you think this could be because of high heart rate? I mean after missionary for example it's like I am tired and my heart is pounding...and I lose the erection, I think that might be from my heart as well. Even with my girl on top If I am thrusting up my heart will start beating really fast and I lose the erection. Any ideas? Anyone ever have this how can I cure this?