Many of my text files are suddenly missing

I am using Manjaro linux with a Samsung SSD 840 Pro. Ive noticed my Documents folder is suddenly empty. After rebooting, most of the text files I had saved are no longer there. The problem is some of these contain passwords such as my BTC wallet, which I only created a few weeks back and do not have a backup, $15,000 is in the wallet. I definitely would not have deleted these files. Are they lost forever and why has this happened?