I can't take photos at the moment as I have no other device on hand to do so. The inside screen down the crease has started to show scratches going down the centre. I wasn't worried at first but now its like it's spreading all the way up the crease and has some discolouration on some parts of the crease. I can't tell if it's the screen or the protector either. Should I be worried and go samsung shop?
Sounds like it's just the screen protector. Best thing is to contact Samsung Customer Support and book a repair. If you can't do without your phone, ask if you can visit a local Samsung Experience Store or Service Centre to get it looked at. I'd say to do this sooner rather than later as the issue is obviously getting worse and don't want to potentially cause any further problems. Hopefully you get it resolved soon and continue to enjoy your device