You have no reason to be disgusted with yourself. You have done nothing wrong. You were a child then and the circumstances that you lived in led you to those actions. I am sure it is not uncommon. There are sexual urges that can be difficult to contain - and if you were a child, you didn't even really know what was going on - only that it felt good.

I hope you discussed this with your psychologist. It has had a giant impact on your self-esteem and your current life. It is critical that you give yourself the chance to work through it.