For Last More Then 35 Years I Cudnt Make Love

for last more then 35 years i cudnt make love with my wife while i have a son but sex point of view i dont know what is joy of sex. due to this i face hell like situation infront of my wife. just after touching my wife without eraction fluid fall and after that penis doesnt come in action.i read about damiapalnt. should i start using that pls. kindly help me. in past i was too much under stress and survived too much with lack of food but today i m happpy by work but i m very sad to looose my sex power. i hope u willl help me to know what is sex and what is it maximum limite to stay with wife. thank you.