You're focusing too much on others and not enough on yourself. Instead of watching others succeed, start something yourself. The way to find what you are good at or like to do is to experiment. Does something catch your interest? Check it out, see what it's like and what it's about. And if you don't like it, then so be it. There's no point in sitting back and thinking anything more on it. Just try out something else, another thing that catches your interest. Keep on doing that, and before you know it, you will have several talents and skills, and on top of that, eventually you will know just what it is that you want to do.
Also, failure is not something to be afraid of. Failure at anything is a learning experience, and studies show that failing at something causes you to learn more than when you succeed at something.
And about your physical looks; everyone thinks they should look any way but the way they do. They always want to 'improve' a certain field of their appearance. In actuality, there is no imperfection in appearance, only those that we are taught to perceive. The media is always displaying images of women that they portray as the image of attractiveness, and other women see this and accept their views without even taking their own views into account. This happens not only to women, but men as well. This causes a sort of guideline mentality, which causes major feelings of insecurity and unworthiness. And worst of all, people who are beautiful and attractive believe that they are not so. Let me tell you a secret about beauty; it's not about fitting into a guideline. It's about being an individual and standing out as one. Just because you don't look the same as some 'model' doesn't mean you aren't attractive.
Another thing I feel should be said here; Don't worry about what others think. Nobody can please or impress everyone, no matter what. The people that don't appreciate you for who you are or can't appreciate the things you do aren't worth your time or effort.
And lastly, I would like to add; If there is something about yourself that is making you unhappy, change it. There is nothing that sitting back and feeling bad about it is going to do for you other than make you feel continuously worse. There is no better time than now to begin working on yourself until you are happy with yourself. The only person you should concern yourself with making happy is yourself, because trying to please everyone else is impossible and will only depress you and make you feel worthless. Work on yourself first, and everything else will come in time.