Premature Ejaculation. My sexual life?

I am married 4 yrs ago. We have a baby. We don't need any more. Me n my wife both r working at different regions but we will meet occasionally. When we do sex I do a lot of foreplay till the penetration, my penis will b erected to the full and when I insert the penis in vagina after just 3 shots semen will b released. I tried lot of times to control it but in vain. By googling it I got to know that I am suffering from premature ejaculation. How to overcome this issue.? Is there any medicines to make my penis erect? I heard a lot of times by using medicines to strengthen my penis we have to face side effects. Is it true..? By d way I drink alcohol occasionally.. Is it effecting my sexual life? I have a fear that if I release the semen again she may got pregnant again and I don't want that. I don't want to use condoms also. Please suggest me a better solution so that we can njoy our sexual life. Thanks in advance.