You likely have what's called a Class II dental malocclusion where the lower jaw is small and retruded relative to the upper jaw. Ideally, you would have the jaw lengthened with surgery (mandibular advancement), but this requires, in most cases, orthodontic therapy. Acceptable compromise procedures include placement of a small chin implant (be extremely careful with this---because of the bony weekness, your chin is short and there is deepening above the chin pad, so too large of an implant can further accentuate this deformity). An alternative, and one that I favor, is what is called a "lengthening genioplasty", when the chin bone is cut, moved slightly forward and downward to actually make this area longer. It has the secondary benefit of softening the crease of above the chin pad to create a natural appearing, longer and stronger/more masculine chin.
Good luck to you!