Locked out due suspicious activity

Hi. I was locked out due to suspicious activity. When i try to log in it asks for a code. I type in the last four numbers of my phone number but does not text my phone. I use my alternate email it emails code but where do i put the code? My microsoft account is hooked to my autistic sons xbox and he is having meltdown because he does not understand. Please help and feel free to ask any questions. I am mentally exhausted from working in this for four days

thanks.