Just my opinion, but when you’re using an email for your own personal business, it is never a good idea to use any commercial service for the address (including iCloud). Pay to get an account with a hosting service and register your own domain to use with your email. My hosting service costs me less that $18 per month, and I have several domains registered. I then create my own email addresses from my own domains and thus those will always be my addresses, even if I moved to a different hosting service.
Back in 2001 after dealing with the very issue you’re facing through the 1990’s, I registered my domains and my personal and other email addresses have never changed once since, no matter how many times I change ISPs or move. You don’t need to use a hosting service for a web site - I don’t have a personal web site, but I do pay for a hosting service to park my domains and keep my email consistent over time, regardless of who provides my home internet service.
A hosting service also, btw, offers typically much more control over your email than other providers of email. I have my own server side white and blacklists (which also allow use of wildcards so entire domains or even countries can be blocked), and advanced server side spam filtering and rules filtering.