Is there anything I can do about my witch chin? (photos)

The witch chin deformity sometimes requires both bony and soft tissue reduction. In some cases, the chin can be shaved and the soft tissue reduced in one procedure. With severe cases, the bony reduction is performed first and then the soft tissue is "tucked" as a second procedure. You have a deep mentolabial fold and narrow chin and I think you would benefit from a reverse genioplasty. I would consider simultaneous submental and jawline liposuction. 

Your 'witch's chin appears to be bony in origin rather than a true witch's chin which comes from soft issue chin pad sagging. In other words this is the natural shape or development of your chin which has gowns more downward than forward. As a result bone reshaping is the procedure of choice. Computer imaging would need to be done to determine the type of change needed that you see as favorable. It is likely that a sliding genioplasty to shorten your chin and change the downward angle of it would provide an improvement appearance.