There were rumours of Sonny Liston being told to KO his opponent's early because the 'squeeze' his handlers had brought for him would leave early if the fight dragged on late, abstaining for Liston had built 'the pressure within' and needed release.
Abstaining from sex for extended period has no physiological benefits but for a testosterone fuelled red blooded male if prevented from some horizontal jogging, you are going to have a aggression in your gut at the cause of your abstention...the opponent.
At end of day if you think not abstaining is affecting your boxing performance then only you can stop yourself from having sex, its self control, same as only you can force yourself to do roadwork on a cold wet day.
Your statement "lacked aggressiveness in them and not stopped guys that i should have KO'd".
Go into the bout to win if a ko occurs then great, but saying you should ko a opponent is in my opinion not in your best interests and in my fighting days i would welcome the opportunity to fight a opponent who felt that they should ko me, as that is their focus rather than them going for the win with bonus of ko if it happened, resulting in me facing a more one dimensional fighter (ko focussed).
What could be better than walking down any street in any city and knowing you're the heavyweight champion of the world?