it is obvious that you become jealous while considering others who are much more pretty than you are. Take it obvious and that's good that you are conscious of this feeling. The only thing you have to do is not to be affected by this feeling and not do any action arising out of this feeling. Take it as obvious. If I had been at your place, I would have been the same personality being affected by jealousy. But we do not have to become guilty conscious nor act arising out of this jealousy.
But transform this feeling of jealousy into compassion or love, whom you are jealous with. But first of all, be technical about it. See, your mind have the habit of comparing your features with others and consequently becoming either jealous or affecting with superiority complex respectively. When you have superiority complex, it is ok with you (though this should not be there), else in the event of getting found yourself as inferior to others, you become jealous or suffer from inferiority complex.
I hope you understand the above.
Now proceeding forward...
Your mind is habitual of comparing...You are lucky getting conscious of it and so, you should not get entangled or trapped in this feeling and rather, transform this feeling deliberately into love or compassion with others whom you are jealous with or whose superior features are disturbing you. I know your mind would obstruct doing such kind act. But you are lucky conscious of it and you can do it.
Now, there is one more fact - you are unique and no other else is like you and can never be and the same is with others too. You are unique and you are new to this world...just new and always new and unique...
Be whatever you are; feel the uniqueness of yourself, feel the newness of yourself...feel the newness and uniqueness of your life...and I hope that this feeling would elevate positively.
According to the above, you should compare to yourself and nothing else and this would uplift your personality...
If anybody is not talking to you, may be he is some restricted by her/ his emotions or some other thing else, but you are free to talk to her / him..so you can...
I think beauty is the aspect of habit of your thoughts or your mind, beautify your mind by positive thoughts (read various literatures) and meditation. May be you are this age, this seems to be somewhat obsolete...but this is the experience of many talents.
Past has gone and future is unknown and is not in your hands. So, there is nothing to worried about. Learn from the past and be alert and prepare yourself for the future.
I would like to recommend the following to go through:
(i) warm up
(ii) Padmasana, Pawanmuktasana, chakrasana, mandukasana, katichakarasana
(iii) Naadi - Shodhana Pranayama (only this one is recommended)
Do the above with consultation with some qualified yoga therapist for few weeks.
