how did you move so smoothly from the key of E (Fb) to the main Db at the beginning of just did a bad thing? i suppose it's because of the A and B in the bass, enharmonic to Bbb Cb so bVI - bVII - I (Mario cadence)? or maybe you dont even know?
when the song starts, i consider that to be C#min (Dbmin). Switching from minor to major key (on the same root) is usually pretty harmless