I recommend putting all your important files into an encrypted container or partition, using VeraCrypt for example.
You will mount that partition only when needed and this will decrease the chances of suspicious programs to access your important files.
It will also make it easier to backup all your important files, as you will need to copy just the single container file.
I would also suggest to install an Anti-Keylogger program such as KeyScrambler to ensure your PC is not being monitored without your consent.
If a keylogger is installed and it bypasses your antivirus, it is still another layer of protection that you have.