I feel as if my mandible is extremely weak. Would a sliding genioplasty make the jaw look bigger or only the chin? (Photo)

I think my chin and jaw are underdeveloped. I am thinking about a Rhinoplasty because I have a big nose that already dwarfs the size of my chin from the side profile and on top of that my jaw doesn't really have an angle, it basically a straight line from my ear. I know neck liposuction could also help, but I'm afraid it would make my jaw/chin area even smaller and make things look even worse. All of my facial proportions are out of whack.