I struggled with this too until I had a scare when my laptop was almost stolen. Since then, I use encrypted folders for all important files. Even if someone gets access to my laptop, they can’t open them. I also make regular backups to secure cloud storage — just in case something happens. The combination of encryption and backup works really well. If you want a clear breakdown of different options,
mobilecon.info explains it really well. That’s where I learned about the tools I’m using now, and it’s made me much calmer about file safety.