After trying many other peoplespeople's solutions, and without success, this answer finally helped me.
https://stackoverflow.com/a/16974197/2433309
In short, running
sudo -u postgres createuser owning_user creates a role with name owning_user (in this case, h9uest). After that you can run rake db:create from the terminal under whatever account name you set up without having to enter into the postgresPostgres environment.