IPhone 5 STOLEN - Erased on FindMyiPhone - Then recovered/got back my iPhone - What to do now?

So my iPhone 5 was stolen, and the police recovered it. Before I got it back I erased it on FindMyiPhone, on iCloud.com. Now when I turn my phone on, it goes in a black screen with the white little rotating loading symbol on the middle of the screen. It's been like this for HOURS! What can I do?
Please help, and srry for bad english. English isn't my first language.
10 points to whoever helps me solve this
I really need my phone for tomorrow so I promise I pick a best answer if someone can help me solve this.

Has your iPhone been fully charged? Also, did you try a hard reset? To reset, press and hold both the Sleep/Wake and Home buttons for at least 10 seconds, until you see the Apple logo.

Go to the place you got it from and ask them if they can fix it, tell him EVERYTHING that has happened, and if that doesn't work, then you might need to charge it, and if that doesn't work, maybe if you can, clean the phone out?

I would just take it to an apple store so they can see if it needs to be fixed.