An email address is not sensitive, and cannot be. Just as soon as you start exchanging email, knowledge of that address spreads. It’s like a mailing address, or a street address. It’s known, and it needs ro be known to be used and useful.
Here are some common scams, a d there are many others:
Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support
You might get password warnings from Apple, particularly if you’ve unfortunately been re-using passwords. Re-using passwords does cause problems just as soon as the passwords becomes known from some breach, this entirely independent of email addresses.
If you’re using an iPhone or iPad, see Settings > Passwords > Security Recommendations.
As far too commonly used in recent years, “dark web” and “hacker” and “virus” are words that commonly mean you’re reading advertising, a scam, or rubbish. You will want to be cautious around these words, not because you are at risk from the “dark web”, “hackers”, or “viruses”, but rather that somebody making claims about these may well be looking to scam you. Or to sell you something you probably don’t need, and that might well be privacy-invasive rubbish.
Switching email addresses because somebody knows the address is… futile. Spammers, some email vendors, marketing folks, and many other entities are all in the business of collecting, acquiring, and selling lists of email addresses. Changing addresses is something I’d generally avoid, particularly as it disrupts those that you do want to communicate with.
