Wow, Thank you soo much thats cracked it. I really want to trust lightroom again.
I think you are missing what LR is. It is a Database program that only References the images you import into the LR catalog.
No images are ever in the LR catalog. The are only referenced into the catalog file, a Database file, from where they are stored on your hard drives. If the hard drive you store your images on fails and you don't have any backups of those images then they are lost just like all other data on the failed drive.
This has nothing to do with trusting LR. The first thing you should do is make a backup of the actual image files to some other drive other than what you use as your main storage location. Whether that is to another drive connected to your system, internal or external, or to some type on online, Cloud, storage location is up to you.
When LR backs up its catalog file it is only that catalog, a database file, that is being Backed Up. Not any of your images.