mnko
The simple answer here as far as I'm concerned is for you to take a step back if at all possible from all your thoughts and feelings, and try and assess what it is that you want. Identify what fears your about getting in touch again, and equally what fears you about not getting in touch. Work out what life is going to be like with the contact as well as without. Most importantly of all, figure out how you will feel if for any reason you get in contact again and all your fears are realised.
Everyone here can only offer advice, but the ultimate decision is down to you. Believe me that keeping that distace away from a parent is incredibly hard, and is actually a lot harder than making contact again. You've made decisions why you don't want contact and why you want to distace yourself from him, so do you really see any difference in situations now.
Essentially, what I'm saying is that you are very confused about what you're feeling right now, so think the best thing is to hold off any kind of contact until you feel better equipped personally to deal with this. A popular view is to put what is going to be your family first, but think you really need to put yourself first. Sounds very selfish, but you've suffered enough and don't deserve to endure any more suffering.
Trust me when I say that you can have a life without parents if you feel that it's not right to have them in your life. Did just that myself as had to break away from both my violent, alcohol fuelled parents, and stayed away for years and years. They never got to see their grandchildren, and didn't see how my life developed, whether good or bad. They have both passed away now. Did make my peace with them before they went because they were still my parents, the people that brought me into this world. My conscience is clear that I did the right thing for me, and my family. Did require strength many times to maintain it, but gut instinct tells