Hi! Welcome to HCM and thank you for your question. You are correct in thinking that your adult height does not depend solely on your genes but also on your diet, physical activity, rest/sleep, and stress
levels among others. The estimated adult height from a single x-ray of your hand when you were 14 was really just a prediction based on the assumption of keeping the factors that can affect growth and development optimal. On average, some growth plates of long bones have already fused by age 18 years. But do not despair! To be sure, try to have your x-rays done again to see if some of your growth plates are still open (also get a chest X-ray to see if your dislocated sternum
, which by the way does not affect your potential height, has returned to its normal configuration). If they are, you may get a few inches in before they close. In the meantime, please continue eating healthy, and do regular exercise. Also, make sure that you get adequate rest (at least 6-8 hours of sleep). Take care!