I think it's important to look presentable for the sake of others, but it's unnecessary to try to be 'sexy' for my own gratification. People have impossible standards for what sexiness is, especially considering the focal point is often times something pretty gross to someone who isn't a hedonist or significant other.

I don't think you have as many flaws as you think you do. The only things that are truly unattractive are medical issues and signs of self neglect, tragic in their own right. There are also intangible reasons for what people might consider beautiful or attractive. But without question, you aren't ugly.

You have an innocent face, a great smile, and what appears to be good health. I didn't need to see you in your undies to know that you aren't ugly (but don't feel bad about that either, as people's taste refines with age, they prefer function over form).