The fear of being judged is the primary reason agents avoid video marketing or cold calling. The secret to pushing through this fear is to shift your focus from yourself to your client. When you are worried about how you look on camera, you are being self-centric. When you focus on the value you are providing to a homeowner who needs to sell, you are being service-centric.
Use exposure therapy. Start small. Record a video and don't post it. Then, record one and send it to a friend. Eventually, post it. The fear never fully disappears; you just develop the "bravery muscles" to act in spite of it.