Do you firstly have an A record in your domain's DNS firstly pointing to your IP address?
Secondly run the command actually specifying the domain name you wan to generate a certificate for
./certbot-auto --apache -d marcchamberlin.com -d www.marcchamberlin.com -v --dry-run
PLEASE NOTE: I have added the --dry-run flag .... this allows you test and see the output and errors before generate a certificate. If you see favourable output running the above then remove --dry-run and it will then generate the certificate for you.