Creativity is at the heart of what we are. If you don't believe you're creative, just look at how wild your dreams are. You are making those dreams up, not some dream directory that you log into every night. It may be a deeper part of yourself, but it is you. Every time you have a conversation you are being creative.
Creativity is unpredictable.
It has to be so that it can be forever new. Having a block is really a form of worship, hanging on, and fear. It is fear of change. There are a few things that contribute to being blocked that can be changed. Learn to relax.