SIR

i m  newly  married guy,during  my  sex with my wife  my pennis  autometically  softens.smtimes  i cumming  once  it also  bcomes soft.it  takes  long time  to errect,by the way  my wife  can,t  satisfy  by me.she wants  a  lot sex.plz  suggest  me  wht  sud  i do  to  errect of  my  pennis? for  what  prob my  pennis   not errecting?