Stop balking at the idea of this letter. It's good to love things about yourself. It doesn't mean that you're selfish.
I love your eyes and the way they're different colors on different days. I love that you've discovered ways to do make-up that enhance your features but have also learned to embrace the au natural. I love that you're aware of your body and the way the things you ingest effect you. I'm glad your health is important to you, not only because you want to look a certain way, but because of the way you want to feel. (P.S.--you're not fat and you know it.)
I love your style and your creativity. You should wear more of those shoes that are sitting in your closet.
I love that you can't help but be a thinker. I know you hate that sometimes, but it's a good thing. It will set you apart and help you succeed. I love that you know, deep down, that the hard times are not here forever, as long as you don't give up. I love that you won't give up. I'm glad you're strong and self-aware, that you know when to compromise and when to stand firm.
I love your ambition. Don't worry that you're not clear on which dream to channel that ambition into. It's coming, just give it time. I love that you do your best to smile and look on the bright side, even though it's certainly easier to be pessimistic and cynical.
There's so much more to love. Don't forget that you deserve it.