It really may be worth talking with a counselor or therapist about the self esteem issue. Alternatively, you may consider finding something you can immerse yourself in, that you're really good at, that challenges you to get better, and work at it and be proud of it. For some women that's knitting, some women it's running, for me, it's rock climbing....for you it may be something else. Use that talent as fuel to say 'yes. *I* did *that*.'
Our looks, no matter what our ages, don't define who we are. Our hair and makeup? It's just, ultimately, decoration. A person can be a beautiful doll like figurine with smooth skin and long lashes etc., but if that person doesn't love herself...or if that person is an ugly person to the people around her...then she's not a person others are going to want to know.
Beauty isn't defined by a genetically gifted exterior. It's defined by what's inside of us and how we use it.