Someone is trying to bruteforce my password with SSH

I have a machine that I can access via SSH. Recently I've noticed that someone (chinese network) is trying to bruteforce their way in. I get 2 tries per second approximately.

I turned on the Firewall, but that doesn't seem to help – The SSH service is still on. So I have turned off SSH in the meantime.

I have a strong password but it's still annoying. What can I do to stop these behaviors?