if you haven't already, consult with a maxfac who is also qualified in aesthetic / plastic surgery. otherwise he will probably be mostly focused on the bite and not on harmonizing the face.
with regard to the genio: you already have a good chin. it is pronounced and has a nice shape. it is just too far back. doing a genio would make it too long and pointy, maybe even give you a witch profile.
the issue are your jaws, which is sadly not easily rectified. you would need at least two premolar extractions in the lower jaw to create some linear overjet for advancement.
let me explain: when you were young and had that 11mm overjet, that 11mm was a somewhat accurate reflection of your skeletal issue. this means, to fix your skeletal base, you are looking at least at a 8-10mm bsso of the mandible. But, as most of us here, you will likely need bimax to fix the full extend of the issue.
that being said, even with the deformity, you are pretty good looking.