What to do if I have craniosynostosis because of my cone shaped head. Anyway to fix carpenters syndrome or craniosynostosis on a teen?

Craniosynostosis. Craniosynostosis is ideally treated in infancy but having said that our center has done a number of untreated adults or adults whose original surgery did not come out well. A consultation with a craniofacial center with multiple sub-specialities that deal with these disorders would be a good place to start.
Leave it alone. This would be a purely cosmetic operation and a very difficult one. Much blood loss and hard on the patient. And you would likely be disappointed with results. The time to fix this is in infancy. After that, it's difficult if not impossible to change head shape.