I am a married male aged 45 having extreme sexual weakness. I do not get hard, stiff penis erections. I used to masturbate before my marriage. When I do get erections they do not last .they are gone after a short duration. I have a 15 years old son and an 8 years old daughter. I ejaculate too early within 30 seconds after entering my wife's vagina. Kindly suggest medicine so that I start getting hard penis erections again and the premature ejaculation problem is solved.