Change has to come from inside, hon, in order to affect the way you interact with the outside world. Appearance is but one facet of the multifaceted jewel which makes up you as a person.
Perhaps a good start to building courage is to think about what courage actually is. It's not a mystical force that one somehow has to possess in order to achieve greatness. All courage is, is the tipping point between not doing something because it scares you, and doing something precisely because it scares you. Doing something in spite of the fear you may feel is empowering in itself, and leads to an increase in confidence which, in turn, makes it easier to undertake the next thing which scares you. It becomes a cycle of empowerment.
The most courageous acts are often the smallest, rather than vast, earthshattering feats of bravery. Resolve to do one thing every day which scares you, something you do not think you can do. It doesn't have to be anything huge. As the old adage goes: a journey of a thousand miles begins with a single step. *hug*