There is nothing you can do about the unsuccessful logins to your email address. My original email address has been in so many hacks and it’s always being brute forced by hackers outside the US.
You already have MFA, so the only other thing I can think of is to have an incredibly long random password on your account and make sure the “forgot my password” recovery flows don’t have any easy way to bypass. Things like another email address as a backup that’s less secure, being able to guess your personal details based on past hacks, easily guessable/researchable security questions (make these random or nonsensical if possible, or don’t put details from security questions in social media) could be used to gain access, even with MFA. And finally, secure your password manager in a similar manner.
Discord server owners can choose to have their members require account verification before joining as an anti-bot measure.