I forgot my password to my account so click on "Forgot your username or password?" A then I wrote my username and after it wrote "The username you provided is not associated with an active Spotify account." And that username is correct.
We’d also suggest having a quick scan of the email accounts you own for emails from ‘email@example.com’. That way, you can determine which one you used to sign up for at www.spotify.com, and then try logging in with this email instead of your username.