Jaw surgery? Injectables? Along with sliding genioplasty (Photo)

Optimal facial balance requires making as many of the facial subunits idealized both individually and also combined to create a cohesive and balanced "whole".
Your features are gorgeous! Having them in the correct location and correct proportion is what creates beauty. Oftentimes, the eye is drawn to the most "objectionable" part of the face and sadly people are disappointed with the results because they became over-focused on what is most displeasing to them.
You may be initially over-focused on your chin positioning, but then later, you may notice that there are other things that are displeasing to you, for example, the subtle downturn at the corners of your lips, which you may interpret as giving you an aging appearance.
It would be challenging to achieve what I presume would be your desired outcome — complete facial harmony — by using fillers or Botox. Fillers are unlikely to provide a satisfying solution.
One can avoid this heartbreaking experience by having a consultation with a surgeon that is trained to analyze the facial skeleton, which is the primary structural foundation that allows the soft tissue of the face to drape and to allow the full range of the expressions of human emotions be expressed in a natural way, which in effect embodies the best parts of each of us.
Namely, a sense of optimism, a sense of acceptance of the self and others, a sense of gratitude, and a sense of hope for fulfilling our hopes and dreams in life.
It is always best to focus on what you truly want rather than what you don't want and don't like. If you want a beautiful and gorgeous face, and you realize that this is an important life goal, give yourself this gift.