After puberty, you penis doesn’t just keep growing. You have reached sexual maturity. It’s decent length with good girth. There are different positions that can make it feel longer insider her too. You really have nothing to worry about when it comes to pleasing girls, just learn to do it right.
a) Your penis length will not fail to satisfy the ladies. All a woman's nerves in her vaginal area are in the front third of the vagina, the rest feels nothing. If your penis were two inches long erect, it would do the trick. Even guys with micropenises can reach her clitoris, which nature has handily placed up top at the mouth of the vagina, so DO NOT FRET about this.
b) Your penis will grow when it feels like it. It is just having you on, again Mother Nature being a trickster. Possibly things would be more rapid in this area if she were Father Nature. Men are so morbidly concerned about penis length.
c) Because of a) above (read it several times), women do not care about penis length. This leaves who? Men. Guys have developed this idea that they are judged by penis length, and the only people who give a hoot are other guys. So, are you really in some kind of penis-length competition with other guys? If so, just look at them smugly and know that it's your care an concern and especially your enthusiasm that will carry the day in sexual activity with the ladies, not your inches. I am a lady and can promise you this is God's honest truth. My best lover was probably 4 inches when erect. He was great, and I cried with he left me to marry an Italian countess.
In short, lighten up! Nothing is wrong, and your penis will add length when it does. Or not, and it doesn't matter. Learn to appreciate the ladies with all your heart, to listen to their stories and share their worries, and cheerfully tell them they are great, and you will have no shortage of women in your life. It's not all about mechanics.