The rising individuality of a man makes him more lonely.You can not grief for what you have been, even if that person served well it was then- at that particular time, moment ..for these particular people.It is natural that you now become a version of yourself that will be in serve to the new time and different kind of people.
You should be happier – this is a new level.
Take your time to grieve, be completely honest and pick yourself from that stage, because you have entered in another- better one, which will fullfil your life with a new purpose.
Enjoy and trust the process…