iphone problems

aight so my desktop with my itunes library has been down since september, and i've just got it working today. i bought an iphone last november sometime and I've never synced it to a computer till now (i didn't expect a 4 month wait for the manufacturer to fix a motherboard), and when I plugged my phone into the computer with itunes to sync some music onto it, an itunes window popped up saying some shit about restoring a back up or something, i didn't think anything of it (thought it was backing up my phone) and low and behold itunes thought my iphone was my brothers old iphone he had from the summer (which i dont get, because my iphone is a 5s and his was a 4s). so basically, it deleted everything from my iphone (all my photos, contacts, apps) and put my brothers shit on it.

i completely reset the phone, and now everytime i connect my iphone to itunes it thinks it's my brothers iphone, so my question bears, is there anyway to stop it from recognizing it as my brothers phone, and is there any chance i could get all my shit back?

thanks

 

Settings > iTunes & App store > Apple ID > Sign Out

Then sign in using your own ID and not your brothers on the phone. Then use iTunes on a different user account or computer than your brother does