I touched the man's private area after he winked at me
That would make me uncomfortable. Why would you touch his private area?
I've already regretted it after I did it,
Touching someone in a private area is molestation. Not only are you sexually abusing them, but you are emotionally harming them as well.
I'm going to turn myself in. I'm sick of it. I'm going to admit everything.
If you feel like this will help then okay. Most of all you should talk to the person and find out if they'll forgive you. If they do then take this as a lesson learned on what not to do next time.