I'm sorry you didn't get a call-back. Please stay positive - there may still be that opportunity you mentioned *sometimes* exists even without a callback.
When I get let-down, I try tell myself that everything happens for a reason. Try take this into your heart and soul and believe it. Explore what the positives would be for not being cast. Is there a lesson to be learnt?

I know it seems hard and like rejection now, but a - there is still a small chance, and b-there may be a lesson to be learnt through this experience.