I have to agree with
@Fjorko.
Why would anyone want to DDoS and average user, just sounds highly unlikely. The resources required to execute an attack like that needs to be warranted, which for a simple home user just ain't worth it.
Plus, the fact that it stopped when you turned off wifi, means it was someone that is within wifi range. So more than likely you had terrible security on your wifi and some clever little knob close by decided to make your life difficult.
Just use WPA2 for the password and apply some additional steps like suggested and you should be good. If someone is spamming your wifi to try and hack the password for it, then yeah, rename SSID and hide it. Or don't hide it and leave it open, but apply mac filtering. That way there is no need for the attacker to even attempt hacking you.