Threemorethings wrote:
... how I can recover the photos? I use iCloud to backup all of my photos.
What do you mean? How are you using iCloud to backup the photos? Is iCloud Photos enabled?
Or are you making iCloud backups of your iPhone?
If you have been using iCloud Photos, make sure, that iCloud Photos is still enabled in the Settings > Your Name > iCloud > Photos and the iPhone is charged and connected to Wi-Fi. There may have been temporary problems with the cloud servers, so it may take a while for your Photos Library to be updated again after the update.
Also, you may want to check on a computer on the web page www.icloud.com, if your missing photos are still in iCloud. Open www.icloud.com in a web browser on a computer, sign in with your iCloud AppleID, open the Photos.app on that page.