Can you login with your user password? If you do that, then you can use sudo passwd root to change your root password; sudo asks for your user password to allow you run the command; and then it asks for the new root passwd.
If you opted to use the same password for your user and root during installation this still applies, considering the passwords are identical, but the accounts are not. However, if that is the case, then, yes, this also means that the boot media route is one of your only remaining options.
Here are brief instructions for that, thanks to @Mirdarthos - if you need them:
- Reset root password (post)
And for additional reference:
- Reset lost root password from the ArchWiki
Cheers.