Before you go off on a crusade and attempt to reconcile with your alienated adult child there are three things to remember:-
THEY WONT CHANGE!
THEY CANT CHANGE!
and most important of all
The best advice I can offer you talking from experience, is to keep moving forward with your life and pursue your hobbies, dreams and aspirations. Be the best possible version of yourself you can possibly be and get on with your life.