Do not internalize the industrial model.  You are not one of the myriad of interchangeable pieces, but a unique human being, and if you've got something to say, say it, and think well of yourself while you're learning to say it better.  – David Mamet

We are taught to conform, to be like everyone else, to obey society's rules.  When it comes to appearance, the current beauty standard is thin and youthful.  Heaven forbid you look fat and old.  Think about how boring the world would be if we all looked the same – had the same body type, same hair style, same clothing, same makeup.  Individuality would whither.  

Your endless, futile, lifelong pursuit of thinness is like a hamster running on a wheel.  You're never going to get to where you think it takes you.  Sure, you could spend the rest of your life diligently counting every calorie and gram of carbs and getting in your prescribed amount of physical activity, but where does that leave you?  I doubt that at your 90th birthday party everyone will say that they are really glad you kept yourself so trim.  What they will appreciate and remember is the difference you made in their lives.  

What we want, what we need, what we must have are indispensable human beings.  We need original thinkers, provocateurs, and people who care.  We need marketers who can lead, salespeople able to risk making a human connection, passionate change makers willing to be shunned if it is necessary for them to make a point.  Every organization needs a linchpin, the one person who can bring it together and make a difference.  Some organizations haven't realized this yet, or haven't articulated it, but we need artists.  

Artists are people with a genius for funding a new answer, a new connection, or a new way of getting things done.

That would be you.  – Seth Godin

What are you passionate about? What activates you at the emotional level and excites you?  How can you use this to make a difference in the world?  You matter and you can make a difference, but you have to choose to.  Choosing not to is also a choice.