Martha Graham (May 11, 1894 – April 1, 1991) was an American modern dancer and choreographer whose influence on dance has been compared with the influence Picasso had on the modern visual arts. Many described her dancing as ugly because her style was so different, and so "contemporary dance" was born.
If you are struggling to convince yourself that you should express yourself creatively you will find a good argument against that critical voice in this quote by Martha Graham.
"There is a vitality, a life force, a quickening that is translated through you into action, and there is only one of you in all time. This expression is unique, and if you block it, it will never exist through any other medium; and be lost. The world will not have it.
It is not your business to determine how good it is, not how it compares with other expression. It is your business to keep it yours clearly and directly, to keep the channel open. You have to keep open and aware directly to the urges that motivate you. Keep the channel open.
No artist is pleased. There is no satisfaction whatever at any time. There is only a queer, divine dissatisfaction, a blessed unrest that keeps us marching and makes us more alive than the others."