Can you be more explicit on what happens (and what you can do and what you can not do) if you boot. It's not clear from your current description, I'm afraid. And please tell your OS.

Maybe your computer has been fine, but somehow it isn't any more. But it ain't clear yet what's wrong with it.

The risk of not doing a regular backup of things you don't want to lose (like your photo's) is that you will lose them if you can't do a last-minute backup. Of course, it is - or has been - your choice to not do it, so don't blame me if they get lost now. But I don't think they will. Wiping a disk is hardly ever necessary. And - unless it's severely broken - it's possible to buy a new hard disk, install the OS on it, then copy the contents of the old disk to it. But even that might be unnecessary.