Dont know how to help my husband

So when my husband was young. Like 12 or younger he asked 2 younger siblings to touch his privates. Based on what he has explained to me and others feel the same way this was born from curiosity not perversion. He was also just a kid. He confessed to his parents and apologized to his siblings and took appropriate measures to not be in that situation ever again.

Since he has had 3 younger siblings been involved with childrens ministries and we have 2 small children and never ever ever ever done anything inappropriate or had any inappropriate thoughts toward any child.

The issue is he is absolutely petrified of doing something wrong even though he has never had a desire to do so since he was between 10-12 and again that was curiosity. And he lives in constant guilt and fear of himself though again nothing has happened and no desire. Idk how to help him overcome this. It's almost like PTSD. I've asked if someone ever did anything to him and he said no. Hes gone into detail about every single instance that happened and I just dont know what to do for him. Or how to better support him.