Q: Accidentally restored?

Hello angheliki,

It depends on where you had the photos stored on getting your photos back after your restore. Let's see what we can do to locate them. 

I would start with looking to see if you have My Photo Stream enabled. If you do, then you should see a collection of photos that were recently synced while you were on Wi-Fi. Open up the Photos app and look in the Albums to see if they show up there. 

My Photo Stream FAQ
https://support.apple.com/en-us/HT201317​

If the photos were recently synced to your computer. You can always sync them back by using iTunes to get them to your iPhone. 

Sync photos from your computer to your iOS device using iTunes
https://support.apple.com/en-us/HT201313​

The last thing I can suggest is putting a more recent backup that you made back on your iPhone. Take a look at the article below for more information about restoring from a back up. 

Restore your device from an iCloud or iTunes backup
https://support.apple.com/en-us/HT204184

Let me know if this helps or need further assistance.

Take care