How do I move on??

So I just found out my husband of 16 years just cheated on me with my cousins g/f, also someone very close to me & my family. I confronted him of course, he was not willing at all. He then admitted to cheating the next day. He is an alcoholic as well. He says that is why he cheated. I honestly don’t think that’s an excuse! He runs away every time I try to talk about his affair. As I’m trying to forgive him & move on, I’m constantly running questions in my head, how long did it last?, How did it end?, What we’re you thinking?, etc.

My question is, am I entitled to details? Am I ‘allowed’ to know details?? I don’t even know what to think. It’s like he admitted to what he did & said ‘sorry’ & everything is supposed to go back to the way it was. I just don’t know how to move on when I’m constantly questioning everything we have been through the past 16 years!! Help me. Has anyone been through this before?? Is there healing to all this madness??