iCloud Storage

A few things to look at.

First, how big is the total storage of your photos? Go to Settings -> General -> iPhone Storage and see if your photos take up more than the 45GB or so of free space you have.

I also noticed that there are 1,405 files that are not listed as photos or videos that you may be able to leave off of the backup and that could give you enough to get all of the photos.

You won't see them in the list of the screenshot you have above. There may be a program that has a lot of storage in it that is checked on for backup.

If you go to Settings -> General -> iPhone Storage, it'll give you a hierarchy of apps and their storage amount on your phone. If you see one at the top that's using a lot of storage, look at your iCloud list and make sure that's not an app being backed up (unless you need it to be).