He hugged his sister when they were both naked
After 23 years I feel miserable. I want to know is my action subject to hadd If I repent do I need to confess so hadd can be carried on me or is repentenc enough.
You have to repent to Allaah from this evil and reprehensible action, and regret what you have done, and resolve never to return to anything like this. Whoever repents, Allaah will accept his repentance, as the Prophet (peace and blessings of Allaah be upon him) said: “Allaah accepts the repentance of the one who repents.” Narrated by al-Bukhaari, 6426; Muslim, 1048.
It is obligatory to repent from the great sin that you have committed. We ask Allaah to forgive us and you, and to help you to repent sincerely.
You deserve to feel sorry and to regret what you did, because a man should protect his family and fight to defend their honour. (Whoever dies defending his honour is a shaheed or martyr). So how could he be the aggressor and sinner? Perhaps this incident will make you more certain of the importance of raising children with moral values and separating them in their beds, and keeping them away from the things that may lead to evil and the things that may provoke desires in them and make them fall into evil.
After all of this we advise you to cover yourself and not tell anyone of what happened. There is no hadd punishment to be carried out on you, rather all you have to do is repent sincerely and do a lot of good deeds (because good deeds wipe out bad deeds).
And Allaah knows best.