Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
I’m sorry you have been unable to access both your account and mailbox, especially when important professional services are connected to them.
Since this began shortly after purchasing the Basic subscription, it would help to separate an account sign-in problem from a mailbox or browser problem. Could you confirm the exact message shown when you sign in at Outlook.com, and whether the same live.com account is still accepted when you sign in to your Microsoft account page?
Please do not post your email address, verification codes, or any other private account information here. Once the exact error is known, it will be easier to identify the appropriate next step without sending you through the same automated recovery loop again.
Thank you for your time