At least it's free
You probably know about password managers. Now I present you a crappy one:
Let's say you want to register for a site:
Now when you login, it is simple. Click "forgot password", and you'll get a new one via email, probably. And then you repeat the same steps.
So your "master" password is your email password. Be sure it is a good one!
Obviously this probably isn't super practical, nor that secure. It also is a simple point of failure; if you can't log into your email for some reason or the "forgot password" button doesn't work then you're screwed. But it's probably more secure than a shitty password used for multiple sites. Oh and always enable two factor authentication! (yes I know I don't like to live in a world where we need our smartphones all the time, but I guess the security of accounts weighs more)
"But wait jopp!!1 if someone hax my e mail, then someone can access all my accunts!!"(except 2fa) Yes that's true, but that's true regardless if you're using a password manager or not.