Lost Password, Recovery Email Address Obsolete

I created a website for my freelance business more than a year ago, but it’s been sitting pretty much unused because I wound up with a full-time job that put my business on the back burner. Now I need to access it and can’t because I have no login information and no longer have the email address that I associated with the website once upon a time. This is how that happened: I use a cloud-based password vault, so I don’t have my passwords memorized or written down anywhere else. When I went to login to the admin page for my WP site today, I found that the password vault had only stored my password, not my username. I can’t retrieve login information via email, because I changed ISPs after moving across the country; the email address associated with my WP site was long ago disabled by my old ISP. I also don’t even remember my username, because I maintain a WP blog and another WP.org site, and those two usernames are the ones that are sticking in my mind. For my freelance site, I’ve tried every possible username I can imagine I might have used, but I’m having no luck remembering. Now I not only can’t update my site but also can’t even shut it down, but leaving it as is really isn’t a good option because it’s so dated–and I don’t want potential clients/employers Googling a dated site. Is there anything I can do or is my site now doomed to live on forevermore as is? If you have suggestions, please explain them to me as though you’re talking to a technology greenhorn, because that’s what I am. Thank you!