You can, you can even probably encrypt your whole drive to add another layer of security if you're that worried. But each additional password to remember is another chance YOU will forget and be locked out, or that you have to record information somewhere, which can be copied or used to gain access.
The safest password is the longest password. Mathematically, a long password consisting of recognizable words is harder to break than one that is much shorter but contains numbers and special symbols and varying case. Of course, it doesn't matter how good a password you have if you don't have adequate malware protection. Malware Bytes and Kaspersky are generally the two go-tos for that particular need.