I lost my National ID. What do I do?

Last June was my graduation and I went home from Cebu to Zamboanga. After I arrived home, checked my things, and that's when I realized my Nat ID is gone from my wallet. My guess would be I left it in the MLhuillier in Cebu that I was last doing a transaction.

Now I'm planning to go back to Cebu to review for my board exam. I will try to go back to the branch I think I lost it but what if I'm wrong? What if wala pala doon? I don't what to do po after that. I need help.