Hello Doctor, My Age 30 Unmarried And I Am Masturbation

Hello doctor, my age 30 unmarried and I am masturbation between 3,4days when i was 16 year.and still do it weakly. My problem is at the sex time my penis not fully eraction and i discharg..so i was some time use seldenafil 50mg but without medicine old conditions my sex life. Before 4,5 years i was alcoholic and adict alprazolem drugs but now i am not alcoholic and not adict any medicine.so please suggest any advise or any medicine how can cured my problem.