What you use as an example input is not the point. Your entire scheme is insecure. It is a fully deterministic scheme from input to output, and reversible as

What you use as an example input is not the point. Your entire scheme is insecure. It is a fully deterministic scheme from input to output, and reversible as well given your suggestion of base64/base128. Passwords should be randomly generated strings of bytes with no deterministic aspect to them at all. Just use a password manager (i.e., https://github.com/zdia/gorilla/wiki https://github.com/zdia/gorilla/wiki) where you can generate random, uncorrelated, unique passwords for each site. Then, using the manager, you don't have to remember the individual unique passwords, it performs that function (remembering) for you. All you need to remember then is your master password to unlock the manager. Once you've begun using a password manager, you'll quickly wonder why you didn't start using it sooner.