You made the first step by telling somebody, even if that person is a stranger.
Think about what/how do you want to manage this situation. Things could change for the best/worst according on how you manage it. I suggest to make a plan before making irational acctions.
Talking with a friend about it could be a start, and then eventually with your mom or a person you trust a lot.
Have you consider seeking professional help about it? Like a counselor so that you can overcome the issue?
- Sometimes when we talk about it we can understand things we didn't exactly understand at the beggining.
You mentioned that you are uncomfortable about doing certain things around him, which is understandable after a situation of this type. The trust has been taken away and you need to decide if you want him to gain it back or cut it because it's harming you.
Ofcourse your dad can still get in trouble because of that. The question is what do you exactly want to do about it. As far as I know if you take it to court it will be hard to prove that he touched you and you would have to have a good case to do something. It really depends. Do you want to move on? Confront him? etc. Define what exactly YOU want to do and what you could give you comfort, peace of mind, etc.
People make mistake and hurt us all the time but that doesn't mean they are horrible people. It's been years since that he could have changed and want to change; you'll never know if you don't give him the benefith of the doubt. It might seem hard, because well why would you cut him some slack if he didn't do the same for you and abused your intimacy in that way? - Well that's a question of if you are able to forget and try to learn to move on, be the bigger person, etc.
Being angry, asking for revendge and all of those things won't change the past. I think that you need to give yourself the opportunity to heal. Now, I'm not saying you need to FORGET your dad about it or anything like that because that's completly up to you, BUT what's important here isn't HURTING YOUR DAD, No.. It's Healing yourself. Learning to deal with it and all fo that. Life isn't fair but we can make it better depending on how we handle this type of things. We don't need to be defined by something that happened in the past.
Do you feel that you are strong enough to talk with your mom and consequently your dad about it? - Perhaps confroonting the situation could be an answer. You might want to give him the chance to say what he feels and if he has done something about it. Speaking about it might give you the peace you want. It's really up to HOW you want to act.