@dreamingofadmin I think first step is to get access to your dashboard.
In Cloudflare, do you have an entry for my.domain.com to your server IP (DNS A record) ? If not, add this manually. Wait a bit. Access https://my.domain.com . If it's asking to accept self signed certs, accept them. Once in dashboard, Domains -> Sync DNS . This will add all the DNS entries. Then, Domains -> Renew all certs.Please let us know what is failing and where.