Whether it was a boy, family, friends, or (God forbid) yourself, there is a reason you opened this article. You don't think you are "enough." You are enough.
Take a look in the mirror at the girl that you are. You are you, and there is nothing more beautiful than that. No one else has the opportunity to live the exact same life as you. You may not see your life as an "opportunity," hell you might despise it, but it is the most unique thing about you. Through the ups and downs, you have been there for yourself. Giving yourself mental pep-talks has probably become a routine part of your day. You are you, and you are your best friend.
You are not your past. People may treat you certain ways because of how you have been in the past. You feel like you wear your mistakes on your forehead, and that your accomplishments are packed away in a box. Surround yourself with people who won't judge you by your past, but with people who will love you for what you accomplish in the future.
As cliche as it sounds, treat yourself. Spend time with yourself. Like I said, you are your own best friend. Spend time with yourself. Go to the gym by yourself, take long drives by yourself, even treat yourself to ice cream or pizza every now and again. If you don't love yourself, your feelings toward others won't be as genuine as they could be. Allow yourself to love you so others can love you too. You deserve it.
Thousands of girls feel like they aren't enough. You are not alone. Look in the mirror, love what you see, and spend the rest of your life knowing your self-worth — and never letting people bring that down.