1. remove your custom page (it has a different lable in the db than the original) because you need to let the plugin create the page.
2. then deactivate the photo plugin (even if you get an error) share that error with us just so we can see it.
3. open up the deactivate folder and run any command manually (if you know how to do that) if you still get an error thats ok.
4. Then uninstall the plugin, if you get an error then open up the uninstall folder of the plugin and run the commands manually if you know how to do that. If you still get an error thats ok, share that with us.
5. Then go to the activate folder and compare that to your database and verify that whatever is created does not exist in the db.
6. Then reinstall the plugin
You are probably getting an error because the server is trying to remove something that does not exist, or trying to create something that already exists.