Oh I think it's perfectly normal to feel guilt, even if you know you are doing the right thing.
He doesn't want the divorce and although you are finished with the "romantic" part of your relationship with him, that doesn't mean he won't be hurt and/or disappointed.
So that's the normal part, who likes hurting someone else?
It means disrupting lives, there is nothing really joyful about divorce that I have found. All you can do is trust that you are doing the right thing and move forward. The other people will survive and carry on with their lives and you, will set yourself free.