I am 27 year old man I have problem during intercourse .my penis does not became as hard as I want during intercourse. It became hard for a few second then it erection and hardness became less and ejection. Come in less hard penis also. I have also a problem of quick ejection last only for maximum 2-3 minute. Please advice what to do. Any medication or exercise? I also have problem of over weight does it matter. My height 5'10f. Weight 94 kg does it effect please advice?