I don't usually comment on here as am I more or less just a lurker but I will say this:

1) Like many people have already said, in no circumstances should you ever try to get in contact with him ever. Not in a million years. I have no doubt he doesn't want to ever see you ever again. Seeing you would be a trigger enough as it is, and then you trying to apologize to him and drag up those memories isn't a burden that he should take. The burden is entirely on you to shoulder your guilt that you were the creator of; he has no responsibility to play any role in you making amends for what you did, and you seeking him out would be another case of you harassing him and harming him for your own benefit. If he's still alive, he's probably managed to move past this horrific act and has moved on with his life. You should leave him be and make amends without dragging him through the experience once again, which at the end of the day would really be only for your sole benefit.

2) Coming to this subreddit and telling your story is honest and that's good, but it isn't this subreddit's responsibility to help you come to terms with what you did, especially when many readers here have gone through exactly what you did to Drew. You have to live with your guilt. That's the actions that you knowingly and dove right into committing, and the consequences of that are yours and yours alone. Never should you try to shoulder it on your victim, or those who have gone through similar things like your victim. It's your role now to figure out how to atone for your actions, but it isn't this subreddit's responsibility, or the responsibility of anybody that had suffered like Drew to give you directions on how to make that happen. That is for you to figure out, with the help of a therapist.

I wish you the best of luck in figuring out what to do in moving past your unforgivable actions and how to make amends. And I hope Drew has found peace after what you did to him.