Lisburn36 on "login problems"

Hi.
I have two domains with wordpress ..(ireallymustfly.com) main domain and(lets-start-anew.com)add on,I have lost the the username and password of the main domain and have been unable to access it for the last few weeks,can you advise me how to recover both of these items as I am trying to launch a website.I have tried so many times but it,s like catch 22 no username no access,can you please help me?
yours sincerely
john mc donald