I’m complaining of premature ejaculation

hello… im complaining of premature ejaculation. condition started 4 years ago. after ejaculation there is immediate loss of erction >>i m not married> i have no any organic disease .no chronic diseases but im smoker about 1-2 cigerrates per day >>i masturbate heaviley for about 8 years about 4 times per week>and ineed to know if there any solutions or suggestions to treat my case or if there is possible medical tretment >>thanks