I am impressed you handled it so well. And yes, it will affect you for a long long time. It's nothing people don't handle; but don't expect this to just completely fade away.
OK, now that I have stated the obvious; how do you know that your H is not in contact with OW? I don't want you to be paranoid; but neither should you be Pollyannish about this. He is on his own and free to do what he wants. What guarantee do you have that he is not seeing her?
I know you do not think a lawyer is neccessary right now (it isn't). But because the first consultation is normally free and you are seperated. I think you should get an idea of what your rights are. I wouldn't pay for anything, but it is good to be prepared.