Try to recover it with your email. If you can still access your Steam without your phone, use it to make the change, but if you don’t have the phone, it will ask for the email that is linked. You also need to know the account name you use to log in. If you don’t have that, then it’s basically lost. Another way to find out which account it is, is by trying to create a new account with the linked email, and it will tell you that there’s already an account created with that email, and then you can try to recover it through the email