I really really hate my big pointed chin and my mandible structure!!! I look horrible when I smile! What can I do? (photo)

You have done a good job of showing exactly how you want your jawline change, it is really the reverse of more traditional v-line jawline surgery. To achieve that effect you need chin reduction to make it horizontally shorter and wider through an intraoral wedge reduction bony genioplasty combined with prejowl implants placed back along the sides the of the chin.

The first image showing the rest position profile is important since it appears to show that the lower lip is "behind" the chin point. The balance between the lower lip and chin is important since animation /smiling will 'pull' the lip inwards towards the lower incisors. This emphasizes the prominence of a chin. So you have to be cautious about reducing the height of the chin and altering the prominence without considering how the lower incisors support the lower lip. So talk to an orthodontist first before altering the chin. Increasing the width I see quite simple but care with shortening the chin since it does age your appearance generally