DNS troubleshooting

In a botched attempt to set up a new MS Team, I have broken my husband's business website and all email is coming back undeliverable. I stupidly/inadvertenly made changes to DNS records on Cloudflare. They are supposedly the only who can help me but I can't get any tech support because it keeps kicking back as saying request must come from account holders email. But that is broken so no email can come from it. HELP