I last masturbated 3 or 4 weeks before. After that suddenly I was getting less erection and not like before .my penis became soft .after 3 or 4 weeks I masturbated and did not get any feeling and my penis now became very soft .then next day I again tried to masturbate but my penis was not standing and was soft and while masturbating I did not got any pleasure, just the sperm came out. I also feel pain in bottom of my penis. Whats the reason?