The End of an Era

I just finished my thesis defense today. It went well, but as I left the university for the last time, something inside me felt strangely hollow. All these years spent researching and writing have been a big part of who I am, yet now that it’s over, I’m not sure what comes next. Should I feel relieved or melancholic? Is this just growing up, or is there more to my feelings than I realize? What should I do when the chapter I’ve dedicated so much time to closes and a new one starts?