transfered domain unable to log in to admin panel

hopefully someone can help!
i recently transfered domain names on my site. through my hosting company, justhost, i was able to copy all content over. and have forwarded old domain to the new one.
BUT i can not longer log into my wp admin panel. i get the normal wp login screen, but my old password/username isn’t working. when i ask for a new password to be sent via email nothing comes.

someone mentioned re-setting my password via cpanel? any suggestions?

thanks in advance.