There is not much more to do at this point but sit back and see if the UFC sues you. From what you said, you downloaded some UFC fights from the site, and apparently the UFC has shut it down and has access to everyone who used the site. My guess is that the UFC will only go after the most egregious offenders, and if you are not one of them, you will probably be passed over.
This answer is not a substitute for professional legal advice. This answer does not create an attorney-client relationship, nor is it a solicitation to offer legal advice. If you ignore this warning and convey confidential information in a private message or comment, there is no duty to keep that information confidential or forego representation adverse to your interests. Seek the advice of a licensed attorney in the appropriate jurisdiction before taking any action that may affect your rights. If you believe you have a claim against someone, consult an attorney immediately, otherwise there is a risk that the time allotted to bring your claim may expire.
There is nothing more you can do at this point. However, it would probably be a good idea to retain an intellectual property litigator to take steps in preparation to defend your case. It is important to preserve your e-mails, computer files, and all other records regarding this matter, as these records may become important in helping you limit the amount of liability an damages which you owe in the event that you are sued. Don't wait until the last minute---take proactive steps to defend yourself by building a relationship with legal counsel.
You are not really scare are you? You are not really a torrent downloader are you? I think you are really a scaremonger working for the UFC trying to warn illegal downloaders. Otherwise you would not be sending in the same basic story over and over and over and over again here. If I am right, you got your message through so enough is enough. I'm wrong and you really are foolish enough to be saying over and over how sorry you are in a public forum where the UFC attorneys can easily Google and catch you, then stop before you cook your own goose.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.