Welcome to the Shopify Community. Sorry to hear you've been having troubles accessing your account. I'd be happy to help.
Have you already tried the forgot my store URL link, which sends an email to the associated email address listing all accounts? If you have not, please try this. Once you know which email address is associated with the account, you can reset your password. If you have followed this link, and are still not seeing your active account by trying any active email addresses, and you're not sure of the email address associated with the current account, the best thing to do will be to contact our Support team directly.
To reach out to our Support team, follow the link to our Contact page, click Continue without logging in, then search for the issue you need help with, for example "login issues" then look for the option to Continue to get support. From there, you'll be able to speak with our team via live chat, email or callback request.
Let me know how this goes and if you have any questions.