Try a full backup with Samsung Kies
http://www.samsung.com/uk/support/usefulsoftware/KIES/Hopefully this will work and save all your photos. If you have an SD card in there they should be saved on that so you can just remove that and store it safely whilst you get the screen repaired.
I guess you are out of warranty by now so you can go to your local market stall for the repair which will be by far the cheapest option.
Just changing the screen shouldn't mean you'd lose anything off the phone so the backup is just to be on the safe side.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)