Hi, I have gone through your query and I understand your concern.. first of all i would like to share with you that masturbation in not an illness.. it is concerned an alternative way to relieve sexual stress, which is quite normal and widely prevalent.. No matter what people around you say about this, masturbation does not cause any illness or deformity Now for your second concern, penis is made up of kind of hollow muscles. when you are sexually excited, blood starts to fill in the hollow of muscles and it gets erected due to accumulated blood. When the excitement is over, blood is withdrawn and muscles again becomes flaccid and penis is directed downward.. it happens with every male now for your third concern i.e premature ejaculation, there are some medicines available in market which helps in this.. also there are some practices known as masters and johnsons techniques, when practiced, benefits in premature ejaculation * sensitize yourself of sexual excitement by initially having foreplay with clothes on, do it without clothes after one week of first step but no sex in third step start having sex, and while having sex when you feel you are about to ejaculate, withdraw and ask your partner to squeeze the top part of your penis.. repeat this few times few more tips * masturbating 2 hours before sex can help * there are local anesthetic sprays available specially for this purpose, when applied before sex, helps in premature ejaculation