I used to used feel the same way at your age, I'm in my 30s now.
Self confidence truly comes from within. It cannot involve anyone else for it to be genuine.
The PP used the example of making herself feel better because she has naturally what others do not (I assume boobs?), but you will find these confidence boosts are fleeting and short lived. Because there will always be someone that has more than you. Or one day you may lose the "object of comparison" and now are back to not feeling good about yourself. i.e. what happens if the PP faces breast cancer and has a double mastectomy, then where is her self worth going to go. (Sorry Paulitens, but I really needed to point this out).
True self confidence does not come from saying "I have this and its better than that person". It comes from saying "I love myself." In my experience (though others might disagree) I find it is better to learn to love who you are first. Your physical appearance can (and will) change, especially with kids and age. Even things like your job, your financial situation, or your spouse can change, and sometimes not for the better and even without you wanting it to. Its good to be grateful for all the wonderful people, things, opportunities, experiences etc in your life, but if you build your self worth on those things and it disappears one day, where will you be? Back to feeling worthless.
I see this a lot with moms. (and I'm a mother of 3) While it is so life changingly amazing to have the privilege and experience of having and raising kids, I see some moms that put all their self value under their performance as a mom. They get all their self love from knowing they are a good mother. Which is fine when your kids are young, but what happens when they grow up and move out? Do you become that over bearing mom that cant give her adult children space to grow and be independent? That guilts them into staying near mom? Do you now feel worthless and useless because you are no longer doing the only thing that made you love yourself; mothering small children?
Anyway I wish I could tell you how to start from within. You need to learn to love the things that make you you! At 19 you might still be figuring it out, maybe. But think of those traits about you that you will take with you in life, the way you are that makes you the friend you are, the student, the daughter, someday maybe the wife and parent, the coworker, the neighbor..etc...Loving yourself is the foundation. Then you can build on it with those other things in life, like your talents, hobbies, education, accomplishments, including weight loss, your appearance....but you need to keep a strong foundation, because if and when someday you must deal with losing something that makes you happy with yourself, your entire world wont crumble around you. For example, you might feel sad about losing a great job that made you feel confident in yourself, but it wont completely take away all yourself worth if you truly love WHO you are, and have the overall confidence to face that kind of loss, and go out and find another job you will excel at.
