You may feel like you are not creative, but you are. Even the thought "I am not creative" is in fact creative. Much of what we do is based on our thoughts about ourselves. Think you can't draw? A trip to the modern art museum never fails to evoke in me the thought "That's art? I could have done that!"
So what does this have to do with shared creative space? Well, it's about choosing to engage in a creative effort (even if you don't feel creative that day) and agreeing to support others who are there for the same purpose. There is a special energy in a like-minded group that engages a different part of ourselves. It allows us to break out of our self-imposed thought prisons that prevent us from trying new things. It is an energy that can break through a writer's block and can support us as we stretch beyond our comfort zone.
Perhaps you haven't noticed group energy before - but next time you go to the DMV, notice what kind of emotion and physical reaction it evokes in you. Then go to a play or live music performance and notice what kind of energy you experience. There's clearly a difference.
So get out there and feed your creativity with some group energy...it might be a writing workshop or a poetry club or an art class or even group counseling (if it includes a creative component). Can't find or afford to participate in a facilitated group? Try going to a museum or sculpture garden to do some sketching; or your favorite coffee house to do some writing; stop and have a conversation with the homeless man who talks in rhythm and rhyme; or volunteer at a children's museum or school to recapture that imaginative and energetic way of exploring the world.