Welcome to Android Central! I'm so sorry this happened to you!
As far as I'm aware, once you initiate a factory reset on the phone, there is no way to retrieve previous data. I'm very sorry.
Did you save any of your photos to Google Drive, or on any other kind of storage other than your phone?
At the very least, if you use social media accounts like Facebook, Instagram, and Twitter, any photos you've uploaded to those platforms could be re-downloaded.