Everyone in the world, big or small, size 0 or 22, Spanish, black, or white, can feel somewhat inferior to others. These things we tell ourselves, that we aren't good or pretty enough, are in no way based on facts. We are a human being, REMEMBER that. God has created us. I am gifted, You are gifted and we are gifted.
Its important to bear in mind that every human being in this world is different, and no two faces or bodies are the same. Your 'inferiority' as you may refer to it can also be seen as a unique or individual quality. What makes you feel these things are 'inferior' to everyone else? If there is no norm amongst human beings, how can there possibly be any form of inferiority?
Life is too beautiful to live. To be reaally happy all the time is not only impossible but unrealistic,but you can make a conscious effort to be happy all the time. However, to be really happy YOU NEED TO ACCEPT YOUR SELF FOR WHO YOU ARE. Listen, nobody is perfect. Spend enough time thinking about your strengths (everyone has them)and you will find yourself more happy, and also more confident! DON'T CONCENTRATE TOO MUCH ON YOURSELF. GET INTERESTED IN OTHERS AND YOU WILL SEE ALL YOUR FEARS AND WORRIES WHICH MAKE YOU SAD MELT AWAY.