Yes, you are worth it. There is no question about that. And, yes, you have done us all proud. Responsibility is joyous. And, I believe you understand this.
Responsibility also is a kind of currency.
Someone gave you some along the way - perhaps someone gave you quite a lot of it. So, it is important that you not shortchange those who gave you this currency. It is important that you not sell short this gift. And, that means taking responsibility for yourselves, taking yourselves just as far as you can go on this currency. That may mean many things to many people, but in the case of the undergraduates in this room, I believe that means going for the gold - achieving a graduate degree.