I'm Leaving My Wife For Her Daughter

She just turned 18 and the attraction we feel is undeniable. Meanwhile, sex with my wife has all but dried up.

My questions are -

Do I have to tell my wife why I'm leaving, and who I'm leaving her for, or can I just go quietly?

For how many years will I have to keep this new relationship a secret, so as not to hurt my wife and not to be subject to scorn and disapproval from family and friends?

Is it wrong for me to have this attraction?

Is it bad if we decide to start trying for a baby?

Thanks for listening. Obviously, there is no one I can turn to for advice about this.