Dear Coping-With-Your-Breast-Size,
First of all, let me commend you on your courage to write in and tackle something that is very important to you and for stepping out of your comfort zone to talk about yourself.
You are definitely right that breasts are a part of a woman’s sexuality. And it seems that all women go through a phase once in their lives where they are dissatisfied with their breasts. Either they are too big or too small. I am sorry to hear that as you feel your breasts are small and that it has affected your self esteem. If it is any help, there are women with big breasts that wish for smaller ones, so you have something that others are longing for.
Though breasts are integral to your physical appearance I think you should not forget it is all of you (physical appearance, intelligence, personality and character) that makes an impact on others and how they perceive you. As you have already mentioned I guess this issue has already affected other aspects of your life as well i.e. your self esteem.
Also, since you're only 19, remember that your breasts have yet to grow as puberty development can go on until 21 years of age. In addition to this, when you start to get sexually active on a regular basis, they will grow, and when you get pregnant and have a baby, they will grow some more.
Nevertheless, I think that having small breasts should not affect your sex life. You have to realize that you are great the way you are and sexuality and sex appeal lie outside of big breasts and long legs. Although it is generally true that men seem to like bigger breasts, not all women have big breasts, and there are many couples who will have a happy sexual relationship that include women with smaller breasts. Think about what attracts you to a man, and whether it is just his appearance or other qualities that may arouse you. This will give you a good indication about the reasons why men are attracted to you or would want to be with you.
Moreover, since you've asked about other aspects of your life, I think you will be relieved to know that having smaller breasts does not affect breastfeeding when and if you have children. It is the amount of fat on your breasts that contribute to their size and this does not affect milk production. Even flat chested women are known to breastfeed with ease.
Other than that, there are many advantages to having smaller breasts. Personal experience makes me say that running is easier, jumping is easier. Wearing a bra all the time not being a requirement – that's another big plus! And I've met my fair share of sexy ladies with small breasts, so don't let that be something to let you down. Your body is a jewel, apart from the fact that it looks beautiful; it also lets you do all these wonderful things and participate in life. So enjoy it!