So you feel inferior, worthless, left out, incompetent. You feel like an ugly duckling stuck in a pond of swans, a loser in a battlefield of the winning, a rag in the posh. At some point in our lives, we do feel that way. It's a phase we all have to go through. But make certain it remains a phase and not a lifestyle. Get back to your feet and start building a better version of yourself.
Remember that every time you feel small, certain areas in your life are calling for change. There must be some things in you that need dropping and there are new things in your path that need absorbing. Embrace change and always think that as long as you're breathing there's hope for improvement.
If you compare yourself with others, you may become vain and bitter; for always there will be greater and lesser persons than yourself. -Desiderata
Develop yourself without setting other people as benchmark. Quit comparing yourself to others! There's no point comparing an apple to a strawberry. You are unique, we all are. Comparing yourself to others would only leave you frustrated. Worse, the green eyed monster might consume you and hinder you from seeing yourself in a light that is your own. Gather inspiration, learn from people's lives but never measure what you are with the same tool used to measure theirs. We lead different lives, we take different paths, we go by different skins. Try comparing yourself from who you were yesterday. Outdo, Upstage, outshine your previous self. And I don't mean this only physically but mentally, emotionally, spiritually and all-the-lly aspect in your life.
Learn. Grow up. Be your better version.