Asalaamu alaikum (peace be upon you) bro qassy. :)
:salamext:
Regret is one of the first parts in the process in repentance, then after that you should pray to Allaah to forgive you, and have the intention never to do that sin again. Then you should try to do lots of good deeds, because Allaah says:
..surely good deeds take away evil deeds...
[Qur'an Hud 11: 114]
Anyway, i know that's not enough so i want you to listen to this lecture by Yasir Qadhi, it's really top masha Allaah and i pray it benefits you in a positive way to draw closer to Allaah ameen:
On the authority of Anas (may Allah be pleased with him), who said: I heard the Messenger of Allah (Peace be upon him) say: Allah the Almighty said:
O son of Adam, so long as you call upon Me and ask of Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you. O son of Adam, were you to come to Me with sins nearly as great as the earth and were you then to face Me, ascribing no partner to Me, I would bring you forgiveness nearly as great at it.
It was related by at-Tirmidhi (also by Ahmad ibn Hanbal). Its chain of authorities is sound.
I invite you to check this link on stories of people who have gone through similar, and how their sin actually helped them draw closer to Allaah and become really pious people:
Stories of Repentance:
http://www.islamicboard.com/islamic-...epentance.html (Stories of Repentance.)
May Allaah forgive you, and us all. ameen. :)
Peace.