There are numerous national (de, nl, etc.) eDarling sites, so it's not possible to give one link. You can find the cancellation option under your account settings easily. Submit the reason why you wish to quit and move on. In the FAQ we read that after cancellation your data will be deleted.
Publicly visible text/images often aren't properly deleted even when you succeed in deleting an account. Try editing or deleting them manually before deleting the account itself. If you're unsure what happens to your tracks you can always contact eDarling and ask personally. By the way, deletion requests don't necessarily mean your data will actually be deleted (e.g. due to legal obligations).
If you signed up for eDarling using a third-party login such as Facebook or Twitter, you probably want to revoke all access from eDarling. Click the icon below to find out how.